Information storage system capable of recording and playing back a plurality of still pictures

ABSTRACT

An information storage medium capable of recording and playing back still picture information is provided with a first information unit having one still picture information, and a first group unit which is composed of a set of first information units, and has a plurality of pieces of still picture information having different contents. Information is recorded in the first group unit.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an information storage mediumcapable of recording and playing back a plurality of still pictures, arecording method and apparatus therefor, and a playback method andapparatus therefor.

[0002] Recently, digital cameras have been prevalently used as media forrecording still image information as digital information. In a DVD thatrecords and plays back video information as digital information, menupictures and the like are displayed as still pictures.

[0003] In a digital camera, individual sensed still pictures are storedas different files. When each still picture information is saved as anindependent file, the following problems remain unsolved.

[0004] a] Since still pictures are not grouped by similarity of contentsor closeness of image sensing times, it becomes troublesome to manageand search individual still pictures.

[0005] b] As an example of troublesome management of still pictures,different files must be opened to check the contents of each stillpicture information, resulting in cumbersome contents checking.

[0006] c] When a plurality of pieces of still picture information are tobe processed in a recording/playback DVD disc, which assurescompatibility and continuity with a DVD Video disc to some extent,compatibility and continuity with the DVD Video disc cannot bemaintained.

BRIEF SUMMARY OF THE INVENTION

[0007] Therefore, the present invention has the following objects:

[0008] A) an improvement associated with the recording format uponrecording still picture information on an information storage medium;

[0009] B) an improvement associated with the data structure ofmanagement information for still picture information recorded on aninformation storage medium;

[0010] C) an improvement associated with an informationrecording/playback apparatus which records still picture information andits management information on an information storage medium; and

[0011] D) an improvement associated with an information playbackapparatus for playing back still picture information and its managementinformation recorded on an information storage medium.

[0012] More specifically:

[0013] A) It is an object of the present invention to provide arecording format and a data structure of management information, whichare used for processing a plurality of pieces of still pictureinformation while assuring data compatibility and continuity of therecording format and management information with a general video schemeof a recording/playback DVD disc that assures compatibility andcontinuity with a DVD Video disc to some extent, and an informationrecording/playback apparatus that can implement such recording formatand data structure.

[0014] B) It is another object of the present invention to provide arecording format and data structure of management information, whichallows easy management and search of a plurality of pieces of recordedstill picture information, and an information recording/playbackapparatus that can implement such recording format and data structure.

[0015] C) It is still another object of the present invention to providean information playback apparatus which allows high-speed access to aninformation storage medium that records a plurality of pieces of stillpicture information so as to continuously display a plurality of piecesof still picture information (continuity upon playback).

[0016] In order to achieve the above objects, a plurality of pieces ofstill picture information are grouped and recorded on an informationstorage medium, thus continuously recording the plurality of pieces ofstill picture information. In the group of the plurality of pieces ofstill picture information, at least two still pictures are continuouslyrecorded at neighboring locations on the information storage medium.

[0017] Also, management information that pertains to the groupedinformation contains map information, which records information whichpertains to each still picture information (e.g., the recording addressof each still picture information on the information storage medium).

[0018] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0019] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate presently preferredembodiments of the invention, and together with the general descriptiongiven above and the detailed description of the preferred embodimentsgiven below, serve to explain the principles of the invention.

[0020]FIGS. 1A to 1F are views for explaining the data structure of aninformation recording medium according to an embodiment of the presentinvention;

[0021]FIG. 2 is a view for explaining the directory structure of datafiles stored in a data area on the medium shown in FIGS. 1A to 1F;

[0022]FIGS. 3A to 3J are views for explaining the data structure in anAV file shown in FIG. 2;

[0023]FIG. 4 is a view for explaining an example of the sequence(recording location) when a video object VOB of AV file data is recordedon the medium shown in FIG. 1;

[0024]FIG. 5 is a view for explaining the data structure in anallocation map table;

[0025]FIG. 6 is a view for explaining the data structure in programchain control information (e.g., user-defined PGC information tableUD_PGCIT);

[0026]FIGS. 7A and 7B are views for explaining playback examples ofvideo information (cell information) based on program chain PGC;

[0027]FIG. 8 is a view for explaining the data structure of managementinformation (video title set information VTSI or management informationRTR_VMGI for video real-time recording);

[0028]FIGS. 9A to 9F are views for explaining the order of sequence ofvideo object VOBs according to video object information (M_VOBI for amoving picture or S_VOGI for a still picture);

[0029]FIGS. 10A to 10L are views for explaining the recording format ofa picture object/audio object for a still picture;

[0030]FIG. 11 shows a screen display example of picture object data(still picture) played back from the medium shown in FIG. 1;

[0031]FIG. 12 is a view for explaining the data structure of informationthat pertains to a video object in a still picture AV file (S_AVFIT)shown in FIG. 8;

[0032]FIG. 13 is a view for explaining the data structure (the datastructure that pertains to S_VOGI in FIG. 9) of a video object unit VOBUin a picture object;

[0033]FIGS. 14A to 14G are views for explaining the relationship betweenthe data structure in a VOB upon continuously recording still pictures,and the designation contents of a corresponding cell;

[0034]FIG. 15 is a view showing an example of the correspondence amongthe data structure cell playback information (cell information S_CI fora still picture) of a picture object, the contents of the cell playbackinformation, and components shown in FIGS. 14A to 14G;

[0035]FIG. 16 is a view showing an example of another data structure ofcell playback information (cell information CI) of a picture object;

[0036]FIG. 17 is a view for explaining the data structure ofpart_of_title (chapter) information that pertains to a still picture inAV file information (S_AVFI) for a still picture;

[0037]FIG. 18 is a view for explaining the data structure of a VOB mapof the picture object shown in FIG. 17;

[0038]FIG. 19 is a block diagram showing an example of the arrangementof a digital video recording/playback apparatus (RTR video recorder)using the medium (a DVD_RTR disc capable of recording/playing back avideo in real time) shown in FIG. 1;

[0039]FIG. 20 is a flow chart for explaining the sequence for recordingone or more still pictures on the medium shown in FIG. 1;

[0040]FIG. 21 is a flow chart showing the sequence when audioinformation is after-recorded on the medium shown in FIG. 1;

[0041]FIG. 22 is a flow chart showing the sequence when one or morestill pictures are played back from the medium shown in FIG. 1;

[0042]FIG. 23 is a view for explaining the data structure of controlinformation/navigation data (RTR_VMG) shown in FIG. 1E or FIG. 8;

[0043]FIG. 24 is a view for explaining the contents of still picturecell information (S_CI) shown in FIG. 23;

[0044]FIG. 25 is a view for explaining the contents of still picturecell general information (S_C_GI) shown in FIG. 24;

[0045]FIG. 26 is a view for explaining the contents of each stillpicture cell entry point (S_C_EPI) shown in FIG. 24;

[0046]FIG. 27 is a view for explaining the contents of still pictureadditional audio file information (S_AAFI) shown in FIG. 12;

[0047]FIG. 28 is a view for explaining the contents of S_AAG generalinformation (S_AAG_GI) shown in FIG. 27;

[0048]FIG. 29 is a view for explaining the contents of an additionalaudio entry (AA_ENT) shown in FIG. 27;

[0049]FIG. 30 is a view for explaining the contents of still picture VOBgroup general information (S_VOG_GI) shown in FIG. 12;

[0050]FIG. 31 is a view for explaining the first example (type 1) of thecontents of a still picture VOB entry (S_VOB_ENT) shown in FIG. 12;

[0051]FIG. 32 is a view for explaining the second example (type 2) ofthe contents of a still picture VOB entry (S_VOB_ENT) shown in FIG. 12;

[0052]FIG. 33 is a view for explaining the third example (type 3) of thecontents of a still picture VOB entry (S_VOB_ENT) shown in FIG. 12;

[0053]FIG. 34 is a view for explaining the fourth example (type 4) ofthe contents of a still picture VOB entry (S_VOB_ENT) shown in FIG. 12;

[0054]FIG. 35 is a view for explaining the relationship between originalPGC information (ORG_PGCI shown in FIG. 8 or 23) and a still picturevideo file (RTR_STO.VRO shown in FIG. 2) when a still picture VOB aloneis recorded;

[0055]FIG. 36 is a view for explaining the relationship between originalPGC information (ORG_PGCI) and a still picture additional audio part(RTR_STA.VRO shown in FIG. 2);

[0056]FIG. 37 is a view for explaining the relationship among a stillpicture VOB, movie VOB, and original PGC information; and

[0057]FIG. 38 is a view for explaining a case wherein user-defined PGCInformation (FIG. 6) looks up a still picture VOB group.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] Preferred embodiments of the present invention will be describedhereinafter with reference to the accompanying drawings.

[0059] [1] Outline of Data Structure on Information Storage Medium

[0060] The recording information contents (data structure) ofinformation recorded on an information storage medium (Optical Disc orDVD_RTR disc 1001) that can record and play back video information andmusic information shown in FIG. 1A will be explained below.

[0061] The data structure of information recorded on the informationstorage medium (optical disc 1001) is roughly divided, in the order frominner side 1006 in FIG. 1B, into:

[0062] lead-in area 1002 having an embossed data zone whose lightreflection surface has an embossed pattern, a mirror zone whose surfaceis flat (mirror surface), and a rewritable data zone capable ofinformation rewriting;

[0063] volume & file manager information 1003 that records informationwhich is recorded on a rewritable data zone which can berecorded/rewritten by the user, and pertains to the entire file orvolume of audio & video data;

[0064] data area 1004 made up of a rewritable data zone that can berecorded/rewritten by the user; and

[0065] lead-out area 1005 made up of a rewritable data zone capable ofinformation rewriting.

[0066] The embossed data zone of lead-in area 1002 records in advance:

[0067] information such as the disc type indicating a DVD-ROM, DVD-RAM,DVD-R, or the like, disc size, recording density, physical sectornumbers indicating the recording start/end positions, and the like,which pertain to the entire information storage medium;

[0068] information such as the recording power and width, erase power,playback power, and linear velocity upon recording and erasure, whichpertain to the recording/playback/erasure characteristics; and

[0069] information such as the manufacturing number and the like, whichpertain to the manufacture of each information storage medium.

[0070] The rewritable data zone of each of lead-in and lead-out areas1002 and 1005 has a unique disk name recording field for eachinformation recording medium, a test recording field (for confirmingrecording/erasure conditions), and a management information recordingfield that pertains to a defective field in data area 1004, and aninformation recording/playback apparatus can record information on thesefields.

[0071] Data area 1004 sandwiched between lead-in and lead-out areas 1002and 1005 can record both computer data and audio & video data, as shownin FIG. 1C. The recording order, each recording information size, andthe like of computer data and audio & video data can be arbitrarilydetermined. Locations where the computer data are recorded will bereferred to as computer data areas 1008 and 1010, and a location wherethe audio & video data are recorded will be referred to as audio & videodata area 1009 hereinafter.

[0072] As shown in FIG. 1D, the data structure of information recordedin audio & video data area 1009 contains:

[0073] anchor pointer for control information 1015: informationindicating the start location (start address) where control information1011 is recorded in audio & video data area 1009;

[0074] control information 1011: control information (corresponding toRTR.IFO shown in FIG. 2) required upon executing respective processes,i.e., video recording (audio recording), playback, editing, and search;

[0075] video objects 1012: video recording information of video datacontents;

[0076] picture objects 1013: still picture information such as stillpictures, slide pictures, and the like;

[0077] audio objects 1014: audio recording information of audio datacontents;

[0078] thumbnail objects 1016: information such as thumbnails used uponsearching for a location the user wants to watch or upon editing; and soon.

[0079] Video objects 1012, picture objects 1013, audio objects 1014, andthumbnail objects 1016 shown in FIG. 1D mean groups of informationclassified in units of contents (data contents). Hence, all pieces ofvideo information recorded on audio & video data area 1009 are containedin video objects 1012, all pieces of still picture information arecontained in picture objects 1013, all pieces of audio information arecontained in audio objects 1014, and all pieces of thumbnail informationused in video information management and search are contained inthumbnail objects 1016.

[0080] VOB (video object) 1403 shown in FIG. 3D (to be described later)indicates a cluster of information recorded in AV file (i.e., audio &video file) 1401, and has a definition different from that of videoobjects 1012 shown in FIG. 1D. Note that similar terms often have quitedifferent meanings.

[0081] Furthermore, as shown in FIG. 1E, the contents of controlinformation 1011 include:

[0082] AV data control information 1101: management information whichmanages the data structure in video object 1012 or manages informationthat pertains to the recording locations on optical disc 1001 as aninformation storage medium;

[0083] playback control information 1021: control information requiredupon playback;

[0084] recording control information 1022: control information requiredupon recording (video/audio recording);

[0085] edit control information 1023: control information required uponediting;

[0086] thumbnail control information 1024: management information thatpertains to thumbnails (thumbnail object) used to search for a locationthe user wants to watch in video data or to edit; and the like.

[0087] Note that Control information 1101 and playback controlinformation 1021 shown in FIG. 1E correspond to RTR.IFO shown in FIG. 2,and RTR_VMG shown in FIG. 23.

[0088] As shown in FIG. 1F, the data structure in AV data controlinformation 1101 shown in FIG. 1E is comprised of:

[0089] allocation map table 1105: information which pertains to addresssetups along the actual layout, identification of recorded/unrecordedareas, and the like on the information storage medium (optical disc1001);

[0090] video title set information 1106: time information (correspondingto RTR_VMGI in FIG. 8) which indicates the overall information contentsin AV file 1401 shown in FIG. 3A, and includes link information amongVOBs, grouping information of a plurality of VOBs for management andsearch, a time map table, and the like;

[0091] video object information 1107: information (corresponding toM_AVFIT/S_AVFIT in FIG. 8 or S_AVFIT in FIG. 12) which indicatesinformation pertaining to each VOB in AV file 1401, and pertains toattribute (characteristic) information in units of VOBUs, and each VOBUcontained in the VOB;

[0092] PGC control information 1103: information (corresponding to PGCIin FIG. 23) that pertains to a video information playback program(sequence); and

[0093] cell playback information 1108: information (corresponding to CIin FIG. 23 or S_CI in FIG. 24) that pertains to the data structure of abasic video information unit upon playback.

[0094] The aforementioned contents are a brief explanation of the datastructure shown in FIGS. 1A to 1F. Some additional explanations of eachinformation will be given below.

[0095] Volume & file manager information 1003 records:

[0096] information that pertains to the entire volume;

[0097] the number of files of contained PC data, and the number of filesassociated with AV data;

[0098] information associated with recording layer information and thelike.

[0099] Especially, as the recording layer information, information 1003records:

[0100] the number of layers that form a disc (e.g., a single RAM/ROMtwo-layered disc has two layers, a single ROM two-layered disc also hastwo layers, and n single-sided discs are counted as n layers);

[0101] a logical sector number range table (capacity in units of layers)assigned in units of layers;

[0102] the characteristics (e.g., a DVD-RAM disc, a RAM section of aRAM/ROM two-layered disc, a CD-ROM, a CD-R, and the like) in units oflayers;

[0103] an assigned logical sector number range table (includingrewritable area capacity information of each area) in units of zones ona RAM area of each layer; and

[0104] unique ID information of each layer (e.g., to find out a discexchange event in a multi-disc pack). With this information, continuouslogical sector numbers can be set even for a multi-disc pack or RAM/ROMtwo-layered disc to handle such discs or disc as a single, large volumespace.

[0105] Playback control information 1021 records:

[0106] information that pertains to a playback sequence which combinesPGCs;

[0107] information (a sequence for continuously playing back allrecorded cells) indicating a pseudo recording location considering theinformation storage medium as a single tape like a VTR or DVC inrelation to the above information;

[0108] information that pertains to simultaneous playback on a pluralityof screens having different kinds of video information;

[0109] search information: information which records cell IDscorresponding to search categories, and a table of start times in agiven cell, and allows the user to select and directly access the videoinformation of interest; and the like.

[0110] Recording control information 1022 records:

[0111] program reservation recording information and the like.

[0112] Furthermore, edit control information 1023 records:

[0113] special edit information in units of PGCs (corresponding timesetup information and special edit contents are described as EDLinformation); and

[0114] file conversion information (which converts a specific field inan AV file into a file such as an AVI file that can undergo specialediting on a PC, and designates the storage location of the convertedfile).

[0115] Thumbnail control information 1024 describes:

[0116] management information that pertains to thumbnail objects 1016(designation information of the recording location of each thumbnailpicture in audio & video data area 1009 and a VOB or cell associatedwith each thumbnail picture, location information in a VOB or cellassociated with each thumbnail picture, and the like (the VOB and cellwill be explained in detail later upon explaining the contents of FIGS.3A to 3J)).

[0117] The directory structure of data files in the data area will bedescribed below.

[0118] All pieces of information are recorded in units of files in dataarea 1004 in FIG. 1B, and the relationship among data files is managedby the directory structure shown in FIG. 2.

[0119] Referring to FIG. 2, a plurality of subdirectories 1451 arecontained within root directory 1450 to allow easy classification inunits of recorded file contents. In the embodiment shown in FIG. 2, datafiles that pertain to computer data recorded on computer data areas 1008and 1010 shown in FIG. 1C are recorded under subdirectory 1457 forcomputer data storage, and audio & video data recorded on audio & videodata area 1009 are recorded under rewritable video title set RW_VTS1452. On the other hand, upon copying video information recorded on aDVD Video disc or (DVD Audio disc) to the disc shown in FIG. 1A, dataare copied under video title set VIDEO_TS 1455, and audio title setAUDIO_TS 1456.

[0120] Control information 1011 in FIG. 1D is recorded as a single filefor recording/playback video management data. In the embodiment in FIG.2, that information has file name RW_VIDEO_CONTROL.IFO (or real timerecording information; abbreviated as RTR.IFO). Furthermore, identicalinformation is also recorded as backup information with file nameRW_VIDEO_CONTROL.BUP.

[0121] In the embodiment shown in FIG. 2, all of video objects(RTR_MOV.VRO) 1012, picture objects (RTR_STO.VRO) 1013, audio objects(RTR_STA.VRO) 1014, and thumbnail objects 1016 are recorded as single AVfile 1401 (the file name in the embodiment in FIG. 2 is RW_OBJECT.OB).

[0122] Rewritable additional information 1454 (not shown in FIGS. 1A to1F) that can be used upon recording/playing back video information canbe simultaneously recorded. That information is recorded as a singlefile, which has file name RW_ADD.DAT (corresponding to S_AA_STI/S_AAFIin FIG. 12 or AA_ENT in FIG. 27) in the embodiment in FIG. 2.

[0123]FIGS. 3A to 3J show an example of the data structure in an AFfile. As shown in FIG. 3B, entire AV file 1401 forms single VTS (videotitle set) (or RTR movie object RTR_MOV.VRO) 1402. VTS 1402 contains agroup of a plurality of VOBs (video objects) 1403, 1404, and 1405, whichare separated into a plurality of part_of_titles (or a plurality ofchapters) 1407 and 1408 in accordance with the contents of audio & videodata and the order of information recorded in AV file 1401.

[0124] VOBs 1403, 1404, and 1405 in FIG. 3D are defined as sets of audio& video data recorded in AV file 1401, and have definition contentsdifferent from video objects 1012 shown in FIG. 1D that primarily servethe purposes of classification items of video information/still pictureinformation/audio information/thumbnail information and the like. Hence,VOBs 1403, 1404, and 1405 in FIG. 3D record not only informationclassified into video objects 1012, but also information classified intopicture objects 1013, audio objects 1014, and thumbnail objects 1016, asshown in FIG. 10.

[0125] Associated VOBs are grouped into a plurality of PTTs(part_of_titles or chapters) 1407 and 1408 based on information contentsrecorded in VOBs 1403, 1404, and 1405. That is, PTTs 1407 and 1408 areformed as sets of one or a plurality of VOBs. In the embodiment shown inFIG. 3C, PTT 1408 is formed by two VOBs, i.e., VOBs 1404 and 1405, andPTT 1407 is formed by one VOB 1403 alone.

[0126] Minimum basic units of video information are called VOBUs (videoobject units) 1411 to 1414, and data in VOBs 1403 to 1405 are formed assets of VOBUs 1411 to 1414, as shown in FIG. 3E.

[0127] MPEG1 or MPEG2 is prevalently used as the video informationcompression technique in VOBs 1403 to 1405. MPEG segments videoinformation into groups called GOPs in 0.5-sec increments, andcompresses video information in units of GOPs. Video informationcompression units of VOBUs 1411 to 1414 are formed to have nearly thesame size as that of GOP in synchronism with GOP.

[0128] Furthermore, VOBUs 1411 to 1414 are recorded while beingsegmented into sectors 1431 to 1437 in units of 2,048 bytes. Sectors1431 to 1437 record raw video information, sub-picture information,audio information, and dummy information in units of packs in the formof pack structures, i.e., V_PCKs (video packs) 1421, 1425, 1426, and1427, SP_PCK (sub-picture pack) 1422, A_PCK (audio pack) 1423, andDM_PCK (dummy pack) 1424. Each dummy pack size is 2,048 bytes. However,since each pack has a 14-byte pack header at the start of it, theinformation size recorded in each pack is 2,034 bytes.

[0129] Note that DM_PCK (dummy pack) 1424 is inserted for the purposesof:

[0130] addition of information to be additionally recorded after videorecording (for example, memo information indicating that after-recordinginformation is inserted into an audio pack and replaced by a dummy packis inserted in sub-picture information (a sub-picture pack) and isreplaced by a dummy pack).

[0131] The recording area of a DVD-RAM (DVD_RTR) disc as an example of te information storage medium (optical disc 1001) shown in FIG. 1A issegmented into a plurality of sectors. 2,048-byte data can be recordedper sector. In this DVD-RAM disc, recording/playback is done in units ofsectors (2,048 bytes). Hence, when a DVD-RAM disc is used as theinformation storage medium (optical disc 1001), the respective packs arerecorded in units of sectors 1431 to 1437, as shown in FIG. 3F.

[0132] As shown in FIGS. 3B and 3D, VTS (video title set or RTR_MOV.VRO)1402 is formed by a sequence of all VOBs 1403 to 1405 in AV file 1401.By contrast, a playback sequence described in playback controlinformation (pack control information) 1021 can designate an arbitraryrange in an arbitrary VOB, and can play it back in an arbitrary playbackorder.

[0133] Basic video information units upon playback are called cells1441, 1442, and 1443. Each of cells 1441, 1442, and 1443 can designatean arbitrary range in an arbitrary VOB, but cannot make designationacross a plurality of VOBs (one cell cannot set a range by linking aplurality of VOBS).

[0134] In the embodiment shown in FIG. 3G, cell 1441 designates one VOBU1412 in VOB 1403, cell 1442 designates whole VOB 1404, and cell 1443designates the range of only a specific pack (V_PCK 1427) in VOBU 1414.

[0135] Information indicating a video information playback sequence isset by PGC (program chain) 1446, and is described by designating asingle cell or by link information of a plurality of cells. For example,in the embodiment shown in FIG. 3H, PGC (program chain) 1446 forms aplayback program as a link of cells 1441, 1442, and 1443 (therelationship between the cell and PGC will be described in detaillater).

[0136] VOBU 1403 in FIG. 3D can contain not only video information butalso audio information. In this case, VOBU 1411 that forms VOB 1403contains V_PCK 1421 and SP_PCK 1422 that construct a video part, andA_PCK 1423 and DM_PCK (for after recording) 1424 that construct an audiopart.

[0137] The video part is formed by a sequence header and GOP headercomposed of some contents on the start side of V_PCK, MPEG I-picturecomposed of the contents of a V_PCK group, a sequence end code composedof some contents on the end side of V_PCK, and sub-picture unit SPUcomposed of the contents of SP_PCK.

[0138] The audio part contains audio data to be played back insynchronism with still picture playback using I-picture of the videopart, and is comprised of one or more audio frames.

[0139] The contents of allocation map table 105 in FIG. 1F will bedescribed below with reference to FIG. 4.

[0140] As described above, the recording area of the DVD-RAM disc issegmented into a plurality of sectors, and logical sector numbers (LSNs)are continuously assigned in ascending order from the inner side.

[0141] A case will be examined below wherein video information isrecorded in data area 1004 of the information storage medium (opticaldisc 1001) in the following sequence.

[0142] 1. An area for recording AV file 1401 is assured in a continuousarea (a<g) from logical sector numbers (LSN) a+1 to g in data area 1004on the information storage medium (optical disc 1001).

[0143] 2. Data of VOB#1 1461 is recorded in a continuous area (b<c) fromlogical sector numbers (LSN) b+1 to c in the area for recording AV file1401.

[0144] 3. Data of VOB#2 1462 is recorded in a continuous area (d<e) fromlogical sector numbers (LSN) d+1 to e in the area for recording AV file1401.

[0145] As a result of the above processes in 1. to 3., three unrecordedareas “from a+1 to b”, “from c+1 to d”, and “from e+1 to g” in logicalsector numbers (LSN) remain in AV file 1401. When video information ofVOB#3 with a large data size is recorded in these unrecorded areas, thefollowing processes are required.

[0146] 4. Data of VOB#3 is segmented into a plurality of data incorrespondence with the unrecorded area sizes in the area for recordingAV file 1401.

[0147] 5. First segmented data 1463 of VOB#3 is recorded in a continuousarea (a<b) from logical sector numbers (LSN) a+1 to b.

[0148] 6. Next segmented data 1464 of VOB#3 is recorded in a continuousarea (c<d) from logical sector numbers (LSN) c+1 to d.

[0149] 7. Last segmented data 1465 of VOB#3 is recorded in a continuousarea (f<g) from logical sector numbers (LSN) f+1 to g.

[0150] As a result, unrecorded area 1460 “from e+1 to f” in logicalsector numbers (LSN) remains in AV file 1401. FIG. 4 shows thedistribution of physical recorded positions of VOBs in AV file 1401 as aresult of the above processes in 1. to 7.

[0151] As can be seen from the above description, when data in AV file1401 is partially erased or when new data is additionally recorded in anunrecorded area in AV file 1401, single VOB data must be segmented andrecorded at a plurality of locations like data 1463, 1464, and 1465 ofVOB#3.

[0152] Allocation map table 1105 shown in FIG. 1F shows informationindicating the distribution of physical positions of identical datadistributed and recorded in AV file 1401 in units of VOBs. FIG. 5 showsthe information contents of allocation map table 1105 taking the dataallocation shown in FIG. 4 as an example. Allocation map table 1105 iscomprised of distribution information 1621 of positions of unrecordedareas, and a plurality of pieces of distribution information 1622, 1623,and 1624 of positions of recorded data in units of VOBs.

[0153] A cluster of data units having continuous logical sector numbersin each VOB will be defined as an “extent”. In the embodiment shown inFIG. 4, data of VOB#3 are recorded as three extents. In the aboveexample, since an area from logical sector numbers a+1 to b hascontinuous logical sector numbers, this area forms “extent#γ 1473”. Thatis, the recording positions of the data of VOB#3 are distributed tothree locations, i.e., extent#γ 1473, extent#δ 1474, and extent#ε 1475.

[0154] The position distribution information that pertains to unrecordedareas or each VOB in allocation map table 1105 shown in FIG. 5 recordsthe number 1601, 1602, 1603, or 1604 of extents at its first position.After that, first address 1606, 1607, 1608, 1609, 1610, or 1611 and size1614, 1615, 1616, 1617, 1618, or 1619 of each extent are recorded. Thefirst address is expressed by a “differential number” (or relativesector number) from the first logical sector number of AV file 1401.When each first address is expressed by a differential number, if theentire contents of AF file 1401 are transplanted to another informationrecording medium, information in allocation map table 1105 need not bechanged, thus improving file portability. In FIG. 5, the extent size isexpressed by the number of sectors. The extent size may be expressed bythe last address of each extent in place of the number of sectors inFIG. 5.

[0155] In the DVD-RAM disc (DVD_RTR disc) format, information indicatinga physical address on the information storage medium (optical disc 1001)is called a physical sector number (PSN), the entire address used by thefile system is called a logical sector number (LSN), and an addressdefined on the file system in data area 1004 in FIG. 1A is called alogical block number (LBN), thus distinguishing PSN, LSN, and LBN fromeach other. However, if this convention is always observed, thedescription becomes complicated. For this reason, FIG. 5 uses anexpression based on logical sector numbers (LSN) for the sake of easyunderstanding.

[0156] The contents of playback control information 1021 will bedescribed below with reference to FIGS. 6 to 7B. PGC (program chain)control information 1103 in playback control information 1021 has thedata structure shown in FIG. 6, and the playback order is determined byPGC and cells. PGC is a unit that designates the playback order of cellsand executes a given playback sequence. On the other hand, each cellindicates a playback period that designates playback data in each VOB bythe start and end addresses, as shown in FIGS. 3D to 3F.

[0157] PGC control information 1103 is composed of PGC informationmanagement information 1052, one or more search pointers 1053 and 1054of PGC information, and a plurality of pieces of PGC Information 1055,1056, and 1057.

[0158] PGC information management information 1052 contains information(number of PGC information) indicating the number of PGCs. Each ofsearch pointers 1053 and 1054 of PGC Information points to the firstposition of each PGC information, and allows an easy search. Each PGCinformation 1055, 1056, or 1057 consists of PGC general information1061, one or more pieces of program information (PGI#m), one or morecell IDs (or CI_SRP#m), and one or more pieces of cell information(CI#m). PGC general information (PGC_GI) 1061 contains information(number of cell playback information) indicating the playback time ofPGC and the number of cells. Or PGC_GI 1061 may contain informationindicating the number of programs (PGs) and the number of searchpointers (CI_SRP) of cell information.

[0159] As shown in FIG. 7A, playback data are designated as a playbackperiod in units of cells from cell-A to cell-F, and PGC information isdefined in each PGC.

[0160] 1. PGC#1 exemplifies a case wherein it is composed of cells thatdesignate a continuous playback period, and its playback order iscell-A→cell-B→cell-C.

[0161] 2. PGC#2 exemplifies a case wherein it is composed of cells thatdesignate an intermittent playback period, and its playback order iscell-D→cell-E→cell-F.

[0162] 3. PGC#3 exemplifies a case wherein playback can be doneintermittently irrespective of the direction of playback or repetitiveplayback, and its playback order is cell-E→cell-A→cell-D→cell-B→cell-E.

[0163] Control information (RTR.IFO) 1011 shown in FIG. 1D or 2 containsnavigation data RTR_VMG (real time recording video manager)corresponding to control information 1101 and control information 1021,as shown in FIG. 1E. This RTR_VMG contains video title set informationVTSI (or information RTR_VMGI of RTR_VMG) 1106, as shown in FIG. 1F.

[0164] This information (RTR_VMGI) 1106 contains information used uponplaying back a sequence of VOBs 1403, 1404, 1405, . . . , shown in FIG.3D.

[0165] The data structure and contents of RTR_VMG in FIG. 1E (or RTR.IFOin FIG. 2) will be explained below with reference to FIG. 8.

[0166] As shown in FIG. 8, navigation data RTR_VMG (control informationRTR.IFO) is comprised of RTR video manager information (RTR_VMGI), amovie AV file information table (M_AVFIT), a still picture AV fileinformation table (S_AVFIT), original PGC information (ORG_PGCI), auser-defined PGC information table (UD_PGCIT), a text data manager(TXTDT_MG), and a table (MNFIT) of information that pertains to themanufacturer.

[0167] RTR_VMGI contained in this RTR_VMG corresponds to video title set(VTS) information 1106 shown in FIG. 1F.

[0168] This information (RTR_VMGI) 1106 contains VTS general information1751, VOB sequence information 1752, PTT information 1753, and VTS timemap table 1754, as shown in FIG. 8.

[0169] Put otherwise, this information (RTR_VMGI) 1106 contains a playlist search pointer table (PL_SRPT) corresponding to VOB sequenceinformation 1752, and a video manager information management table(VMGI_MAT) corresponding to VTS general information 1751.

[0170] Table PL_SRPT contains information 1756 indicating the number ofVOBs in VTS (or the number of play list search pointers and the endaddress of PL_SRPT), information 1757 indicating the ID of the first VOBin a VOB sequence (or first play list search pointer PL_SRP#1),information 1758 indicating the ID of the second VOB in the VOB sequence(or second play list search pointer PL_SRP#2), and the like.

[0171] Each play list search pointer (PL_SRP) contains information(PL_TY) indicating the type of a play list, PGC number information(PGCN) corresponding to this play list, information (PL_CREATE_TM)indicating the date of creation of this play list, information(PRM_TXTI) of primary text associated with this play list, numberinformation (IT_TXTI_SRPN) of a search pointer of item text used in thisplay list, and thumbnail pointer information (THM_PTRI) indicating athumbnail picture corresponding to the recording contents of this playlist.

[0172] The table (PL_SRPT) that contains these pieces of information1756, 1757, 1758, . . . corresponds to VOB sequence information 1752contained in VTSI (RTR_VMGI) 1106.

[0173] The contents of VTSI (RTR_VMGI) 1106 can be summarized asfollows.

[0174] That is, as shown in FIG. 8, the data structure in video titleset information (or RTR_VMGI) 1106 records:

[0175] video title set general information 1751 . . . This informationpertains to general contents of a video title set (or RTR data in AVfile 1401 in FIG. 2);

[0176] video object sequence information 1752 . . . In the datastructure shown in FIGS. 3A to 3J, serial numbers are set for all VOBsin video title set 1402 (=AV file 1401). This information describesserial number information of VOBs according to this sequence;

[0177] part_of_titles information 1753 . . . Object data recorded in AVfile 1401 are grouped in units of associated data for the purpose ofeach data management and search, and video title names are set in unitsof groups. The group (part_of_title) is formed of a set of VOBs. Thisinformation describes VOB information contained in each part_of_title;and

[0178] video title set time map table 1754 . . . This informationpertains to VOBU position information at specific time intervalsaccording to the video object sequence in relation to VOBs which areclassified into video objets 1012 and audio objects 1014 in video titleset 1402.

[0179] The detailed data structure in video object sequence information1752 is shown on the right side in FIG. 8. That is, the total number1756 of VOBs (or PL_SRPTI) contained in the video title set is recordedat the first position. After that, VOB_IDs (or PL_SRP#1, PL_SRP#2, . . ., PL_SRP#n) 1757, 1758, . . . corresponding to serial numbers arerecorded in the sequence (video object sequence) order.

[0180] The sequence indicated by video object sequence information 1752can be arbitrarily set by the user or information recording/playbackapparatus side in, e.g., “the recording order to AV file 1401 (ascendingorder of recording time)”, “the recording allocation order on theinformation storage medium (optical disc) shown in FIG. 4”, “the VOBsize order”, and the like. By sequentially determining the order of allVOBs in VTS (video title set) 1402, a user interface similar to a VTRthat records video data on a single table can be provided.

[0181] For example, the following processes can be done using videoobject sequence information 1752:

[0182] to search for a scene the user wants to watch by fast-forwarding(FF) or rewinding (FR) a tape;

[0183] to confirm the entire recording contents by fast-forwarding (FF)the tape; and

[0184] to search for an unnecessary recorded scene by fast-forwarding(FF) or rewinding (FR) the tape, and to overwrite new video informationon that scene.

[0185] The information contents of video object sequence information1752 shown on the right side in FIG. 8 will be explained below withreference to FIGS. 9A to 9F. A case will be examined first wherein VOB#1to VOB#3 are recorded to have the allocation order on the informationstorage medium (optical disc) shown in FIG. 4, and this recording isdone in the order of 1. to 7. described in “description of allocationmap table contents”. FIG. 9C shows the sequence order which is set forthese data in “the recording order to AV file 1401 (ascending order ofrecording time)”. Compared to FIG. 4, the allocation order from extent#α1471 to extent#ζ 1470 has changed. “First VOB_ID 1757 in the videoobject sequence” shown in FIG. 8 designates “VOB#1 1461” in FIG. 9C, and“second VOB_ID 1758 in the video object sequence” designates “VOB#21462” in FIG. 9C.

[0186]FIG. 9F shows another embodiment designated by video objectsequence information 1752. VOB#A 1771 and VOB#B 1772 belong to (areclassified to) video objects (movie VOB information M_VOBI#) 1012, VOB#C1773, VOB#F 1776, and VOB#G 1777 to audio objects 1014, and VOB#D 1774and VOB#E 1775 to picture objects (still picture VOB group informationS_VOGI#) 1013. In this way, the sequence order can be designatedindependently of the VOB types. In FIG. 9F, VOBs (VOB#H 1778 and VOB#I1779) that belong to thumbnail objects 1016 are set at the end of thesequence.

[0187] The recording format upon recording still picture information onthe information storage medium (optical disc 1001) shown in FIG. 1A willbe explained below.

[0188] Still picture information or audio information (information thatadditionally records audio data of a comment for each still pictureinformation by after recording) to be added later to still pictureinformation are recorded at a location of picture objects 1013 or audioobjects 1016 in FIG. 1D. For example, the format is designed to becapable of continuously recording a plurality of still pictures assumingthat a plurality of still pictures sensed by a digital camera arerecorded on the information storage medium (optical disc 1001) at onetime. In order to allow to continuously record a plurality of stillpictures, the format is designed to record at least two still picturesat neighboring locations on the information storage medium (optical disc1001).

[0189] A still picture or audio information to be added to the stillpicture follows the data structure shown in FIGS. 3A to 3J to attainformat continuity and matching with video information (video objects1012). In MPEG1 or MPEG2 as one type of recording format (videoinformation compression format) of video information, compressedinformation for one corresponding video frame is present at the startposition of the aforementioned GOP in the form of “I-picture”.

[0190] As shown in FIGS. 10C and 10I, input still pictures are convertedinto I-pictures 1706, 1707, 1708, and 1709 using the MPEG1 or MPEG2compression technique, and these I-pictures are recorded on theinformation storage medium (optical disc 1001) while being stored inV_PCKs (video packs) 1661, 1662, 1663, 1668, 1669, 1670, 1671, 1672,1673, and 1674.

[0191] As described above, on the DVD-RAM (DVD-RTR) disc, each V_PCK(video pack) is recorded in units of sectors each having a recordingsize of 2,034 bytes (see FIG. 3F) [one sector size is 2,048 bytes, butsince each pack has a 14-byte pack header, the recording size per packis 2,034 bytes].

[0192] When the I-picture size corresponding to one still pictureinformation is smaller than an integer multiple of 2,034 bytes, dummyinformation 1704 is recorded in that short field. In this way, eachI-picture can just fall within an integral number of sectors.

[0193] Since I-picture size 1808 in each VOBU is recorded in informationof a VOBU map for picture objects, as shown in FIG. 13 (to be describedin detail later), the start position of dummy information 1704 in V_PCK(video pack) 1670 can be determined. Hence, the contents of dummyinformation 1704 can be arbitrarily set.

[0194] For example, as the contents of dummy information 1704, forexample, a sequence end code (or a packet header with stream ID=0×be)can be recorded as specific information which can be specified as dummywhen it is played back, in addition to padding data with all “0”s or all“1”s.

[0195] Note that allocation of I-pictures is omitted in FIGS. 1OF and10L, but the data has the same structure as in FIGS. 10C and 10I.

[0196] For example, when a still picture is sensed using a digitalcamera, and some comment is to be directly added by handwriting on thatsensed picture (still picture), the information of the comment contentscan be recorded as a sub-picture stream in SP_PCKs (sub-picture packs)1681, 1682, and 1683 in addition to the still picture recorded asI-picture in V_PCK. Upon playback, I-picture still picture informationin V_PCK and sub-picture information in SP_PCKs are displayed to overlapeach other.

[0197] Audio information that stores a comment for each still picture asaudio data is recorded in A_PCKs (audio packs) 1691 to 1702.

[0198] In this manner, V_PCKs 1661 to 1674, SP_PCKs 1681 to 1684, andA_PCKs 1691 to 1702 are gathered in units of associated still pictures,and are grouped in units of VOBUs (video objects for picture objects)1641 to 1650. Hence, in the format shown in FIGS. 10A to 10L, each stillpicture forms one VOBU.

[0199] In the embodiment shown in FIGS. 10A to 10L, V_PCKs and SP_PCKare recorded before A PCKs in each VOBU. As a result, the individualpacks are separated in each VOBU, and information in each pack can beeasily managed.

[0200] However, the embodiment of the present invention is not limitedto the aforementioned limitation, and allows to allocate A_PCKs, V_PCKs,and SP_PCKs in an arbitrary order as in the recording format in videoobjects 1012.

[0201] Furthermore, V_PCKs 1664 having still picture informationrecorded in the I-picture format must be allocated in single VOBU 1642,but A_PCK (1694) that records part of audio information associated withVOBU 1642 can be allocated in next VOBU 1643.

[0202] As will be described later with reference to FIG. 13, continuousaudio information can be separated in correspondence with each stillimage using information of E_PTM (presentation terminating time) 1814 ofaudio information recorded in VOBU map 1738 for picture objects.

[0203] As the format that can continuously record a plurality of piecesof still picture information, the format structure shown in FIGS. 10A to10L permits the following two different methods and mixed recording byboth the methods.

[0204] 1) One VOB is formed of a plurality of VOBUs.

[0205] 2) One VOB has only one VOBU, and VOBs each of which records asingle still picture are grouped to construct VTT (video title).

[0206]FIGS. 10D to 10L show the former format structure 1), and FIGS.10A to 10C show the latter format structure 2). In the former formatstructure 1), FIGS. 10D to 10F show the basic structure. As specialexamples, FIGS. 10G to 10I show a structure which does not include anyaudio information (A_PCK), and FIGS. 10J to 10L show a structure whichdoes not include any original still picture (V_PCK). After a pluralityof pieces of still picture information which do not contain any audioinformation and are sensed by a digital camera are recorded on theinformation storage medium (optical disc 1001) at one time, the user mayoften input memo data (additionally recorded as SP_PCK) or audio data(additionally recorded as A_PCK) for each still picture while observingthe plurality of pieces of recorded still picture information. In suchcase, efficient editing and recording can be done when only additionaldata (memo and audio data) are gathered to form and record a VOBdifferent from that which records original still picture information, onthe information storage medium (optical disc 1001). When additional dataare recorded as another VOB, the contents of a VOB that records originalstill picture information need not be changed. In this fashion, therecording format in VOB 1634 that gathers only additional data (memo andaudio data) for the purpose of easy editing for still pictureinformation has a structure (which contains only A_PCK and SP_PCKwithout any V_PCK) similar to that shown in FIGS. 10J to 10L.

[0207] Note that I-picture data shown in FIGS. 10C and 10I correspondsto that shown in FIG. 3J, and dummy data shown in FIGS. 10C and 10Icorresponds to dummy pack DM_PCK shown in FIG. 3F.

[0208] Also, video pack V_PCK, sub-picture pack SP_PCK, and audio packA_PCK shown in FIGS. 10A to 10L respectively correspond to V_PCK,SP_PCK, and A_PCK shown in FIG. 3F.

[0209] Dummy pack DM_PCK shown in FIG. 3F or FIGS. 10C and 10I can beappropriately used for the purpose of audio data after recording and thelike. For example, when the size of an encoded I-picture data clusterdoes not match an integer multiple of the block size (16 sectors/32kbytes) of an error correction code (ECC) that uses a product code,DM_PCK can be added to this data cluster as needed so that the I-picturedata cluster size matches an integer multiple of 32 kbytes.

[0210] When the cluster sizes of all I-picture data that form stillpictures are matched with an ECC block unit (an integer multiple of 32kbytes) by adding DM-PCK, the following merits are obtained.

[0211] For example, when one of a plurality of still pictures that havebeen continuously recorded on the medium shown in FIG. 1 is replaced byanother still picture (or erased), since the still picture (I-picture)to be replaced (or erased) has an ECC block unit even if it has a sizedifferent from the original still picture, the ECC block units ofI-pictures which are not replaced (not erased) are not disturbed.

[0212] For this reason, even when one of still pictures is replaced byanother still picture (or erased), ECC coding of I-pictures which arenot replaced (not erased) need not be redone. Since ECC coding need notbe redone, the operation speed of an RTR recorder can be improvedaccordingly, and recorded still pictures can be smoothly edited (toreplace or erase some still pictures).

[0213] However, when the size of a still picture to be replaced islarger than the original still picture size, the still picture data tobe replaced is partially recorded at another recording location. Thatis, the replaced still picture gets fragmented. When the seek speed of adisc drive that reads out data from the medium shown in FIG. 1 is low,playback of the fragmented still picture requires a relatively longperiod of time. Hence, when an RTR recorder having no high-speed driveis used in playing back still pictures, the recorded data are preferablyarranged (to be re-recorded to remove fragmentation) as needed.

[0214] When the latter format 1) shown in FIGS. 10A to 10C is adopted asthe format that allows to continuously record a plurality of pieces ofstill picture information, a plurality of VOBs are grouped, as shown inFIG. 3C, to belong to different groups of VTTs (video titles) 1407 and1408.

[0215] The recording format shown in FIGS. 10A to 10L can record atleast two still pictures at neighboring locations on the informationstorage medium (optical disc 1001), and can continuously record aplurality of still pictures in general. For this reason, for example,when a plurality of still pictures sensed by a digital camera arerecorded on the information storage medium (optical disc 1001) at onetime, a practical effect and feature can be obtained, i.e., quickrecording can be attained.

[0216] In addition, the recording format that can record a plurality ofstill pictures in a VOB has the following practical effects.

[0217] In the conventional recording format for a plurality of stillpictures sensed by a digital camera, still pictures are divisionallyrecorded one by one in different data files. When still pictures aredivisionally recorded in different files, neither image sensing orderinformation among still pictures nor grouping information among stillpictures are available. By contrast, a negative film (or a positive filmprepared as needed) is available in case of a photographic film. Forthis reason, when a specific still picture is to be designated uponmaking an additional print, a still picture to be printed can be foundby a search on the negative film in the photographing order.

[0218] In an information recording/playback apparatus (video recorder)for recording video information shown in FIG. 19, information of videoobject 1632 for picture objects recorded on the information storagemedium (optical disc 1001) is read, and still pictures can be displayedon the screen in the allocation order of VOBUs 1642 to 1644 like apositive film shown in FIG. 11. For example, a still picture at the leftend in FIG. 11 expresses information of VOBU 1642, and the central stillpicture expresses information of VOBU 1643. The still pictures shown inFIG. 11 can be moved to the right or left on the screen, and the userdesignates a still picture to be edited (or to be hard-copied). Unlikevideo objects 1012, still picture information designates an individualstill picture using the display shown in FIG. 11. (In video objects1012, the video information range to be edited is designated by thedisplay or presentation time.) The data structure in video objectinformation that pertains to still picture information will be explainedbelow. Video object information (or AVFIT) shown in FIG. 1F is dividedinto a management information field (M_AVFIT in FIG. 8) that pertains togeneral video information, and a management information field (S_AVFITin FIG. 8) that pertains to still picture information. FIG. 12 shows thedata structure in the latter management information field (S_AVFIT) thatpertains to still picture information.

[0219] The still picture AV file information table (S_AVFIT) containedin navigation data RTR_VMG shown in FIG. 8 contains still picture AVfile information table information (S_AVFITI), still picture VOB streaminformation (S_VOB_STI#1 to S_VOB_STI#n), still picture AV fileinformation (S_AVFI), still picture additional audio stream information(S_AA_STI#1 to S_AA_STI#m), and still picture additional audio fileinformation (S_AAFI), as shown in the left column in FIG. 12.

[0220] The still picture AV file information (S_AVFI) contains VOBinformation (or S_AVFI general information S_AVFI_GI) 1721 for pictureobjects management information, search pointer #1 (or still VOB groupinformation search pointer S_VOGI_SRP#1) 1726 of VOB information forpicture objects, . . . , #i (S_VOGI_SRP#i) 1727, . . . , #k(S_VOGI_SRP#k) 1728, and VOB information #1 (or still picture VOB groupinformation S_VOGI#1) 1731 for picture objects, . . . , #i (S_VOGI#i)1732, . . . , #k (S_VOGI#k) 1733, as shown in the central column in FIG.12.

[0221] VOB information #i for picture objects (or still picture VOBgroup information S_VOGI#i) has the contents shown in the right columnin FIG. 12 (the same applies to VOB information #1 and information #kfor picture objects).

[0222] That is, VOB information #i for picture objects is comprised ofVOB general information 1736 for picture objects (or still picture VOBgroup general information S_VOG_GI), VOB attribute information 1737 forpicture objects, and VOBU map 1738 for picture objects (or one or morestill picture VOB entries S_VOB_ENT#).

[0223] Note that S_VOG_GI contains the number (S_VOB_Ns) of VOBs, astill picture VOB stream information number (S_VOB_STIN), timeinformation (FIRST_VOB_REC_TM) indicating the recording time of thefirst VOB in that VOB group, time information (LAST_VOB_REC_TM)indicating the recording time of the last VOB in that VOB group, and thestart address (S_VOG_SA) of the VOB group in a still picture AV file.S_VOG_SA expresses a relative address from the first address of S_AVFIin units of sectors.

[0224] On the other hand, S_VOB_ENT# includes four types (types 1 to 4),which respectively have the following contents:

[0225] (1) S_VOB ENT of type 1 contains information (S_VOB_ENT_TY)indicating the type of VOB entry of a still picture, and information(V_PART_SZ) indicating the video part size in a still picture VOB inunits of sectors.

[0226] (2) S_VOB_ENT of type 2 contains information (A_PART_SZ) thatexpresses the original audio part size in a still picture VOB in unitsof sectors, and information (A_PB_TM) that expresses the playback timeof this audio part in units of video fields, in addition to S_VOB_ENT_TYand V_PART_SZ of type 1. When the playback time of an actual audio partdoes not match a boundary of video fields, data after the video field ofend data of the audio part is discarded.

[0227] (3) S_VOB_ENT of type 3 contains number information (S_AAGN) ofan additional audio group contained in an audio stream added to a stillpicture VOB, and information (AA_ENTN) of an entry number correspondingto this sill picture VOB additional audio stream, in addition toS_VOB_ENT_TY and V_PART_SZ of type 1.

[0228] (4) S_VOB_ENT of type 4 contains S_AAGN and AA_ENTN of type 3 inaddition to S_VOB_ENT_TY, V_PART_SZ, A_PART_SZ, and A_PB_TM of type 2.

[0229] S_VOB_ENT of each of types 1 to 4 commonly contains S_VOB_ENT_TYand V_PART_SZ of type 1.

[0230] Note that each S_AA_STI (#1 to #m) in the left column in FIG. 12contains audio attribute information of an additional audio stream. Fromthis viewpoint, S_AA_STI corresponds to VOB attribute information 1737in the right column of FIG. 12.

[0231] A plurality of pieces of still picture information grouped todifferent video objects for picture objects (VOBs for picture objects)are recorded in video object information 1731 for picture objects tovideo object information 1733 for picture objects (or S_VOGI#1 toS_VOGI#k) in FIG. 12.

[0232] The information contents shown in the right column in FIG. 12will be briefly explained below.

[0233] Information 1732 contains the following information:

[0234] *VOB general information 1736 for picture objects (or S_VOG_GI)

[0235] ID information uniquely set in units of VOBs so as to designate aspecific VOB in, e.g., cell playback information (CI in FIG. 1F or S_CIin FIG. 23) 1108;

[0236] VOB type information . . . information indicating informationshown in FIGS. 10A to 10L to which the VOB belongs, informationindicating video information (video objects 1012)/still pictureinformation (picture objects 1013)/audio information (audio objects1014) to which the VOB pertains, and the date of recording of the VOB onthe information storage medium (optical disc 1001);

[0237] *VOB attribute information 1737 for picture objects

[0238] attribute information such as resolution or the like of stillpicture and/or attribute information of audio information,

[0239] the number of pieces of sub-picture information, recordingformat, and the like;

[0240] *VOB map 1738 for picture objects

[0241] . . . information that pertains to all still pictures included ina VOB.

[0242] Video object information 1721 for picture objects managementinformation contains the following information:

[0243] the number of VOBs for picture objects contained in this AV file;

[0244] general information that pertains to VOBs contained in this AVfile; and the like.

[0245] Also, address data indicating the recording locations of aplurality of pieces of video object information 1731 to 1733 for pictureobjects in video object information 1107 shown in FIG. 1F are recordedin search pointers 1726 to 1728 of video object information for pictureobjects.

[0246] The data structure in VOBU map 1738 for picture objects will beexplained below with reference to FIG. 13.

[0247] As shown in the central column of FIG. 13, the number of stillpictures contained in the corresponding VOB (i.e., the number of VOBUs;or number of such VOBs S_VOB_Ns) 1801 is stored at the beginning of VOBUmap 1738 for picture objects (S_VOB_ENT#). Information (1802, 1803,1804, . . . ) that pertains to each still picture (contents of a VOBU)follows in the allocation order in a VOB.

[0248] As the information (e.g., 1803) that pertains to each stillpicture (contents of a VOBU), information shown in the right column inFIG. 13 is recorded.

[0249] Referring to FIG. 13, information 1807 of VOBU 1411 (FIG. 3E)having one still picture information which also contains audioinformation is divisionally recorded on a plurality of sectors 1431 to1434, as shown in, e.g., FIG. 3F. Data size (V_PART_SZ and/or A_PART_SZ)1806 for one still picture information (VOBU) is indicated by the numberof sectors used in divisional recording.

[0250] In case of a VOBU which includes A_PCK (audio pack), as shown inFIGS. 10A to 10C or FIGS. 10D to 10F, display time 1807 of one stillpicture means the playback time of audio information in a VOBU. On theother hand, in case of a VOBU which includes no A_PCK (audio pack), asshown in FIGS. 10G to 10I, display time 1807 means the still displayperiod of a still image.

[0251] As information that pertains to still image information itself ina VOBU that records one still picture information, the followinginformation (the right column in FIG. 13) is recorded.

[0252] *start V_PCK address (or S_VOG_SA) 1808 in the corresponding VOBU

[0253] . . . Taking FIGS. 10A to 10L as an example, address data ofV_PCKs 1661, 1664, 1665, 1666, 1667, 1668, 1671, 1674, and the likelocated at the start positions of VOBUs are recorded. When the ID of aVOB that contains a still image the user wants to watch, and the stillpicture number (VOBU number) in that VOB are designated, an optical head(not shown) directly accesses the start V_PCK address of thecorresponding VOBU using this address data.

[0254] In general, as address information, the LAN (logical sectornumber) directly indicating the position on the information storagemedium (optical disc 1001) is used, as shown in FIG. 4. However, thepresent invention is not limited to such specific address indicationmethod, and other application examples are available. For example, asshown in FIG. 9C, the address on the medium may be indicated by thenumber of sectors (relative address) by counting sectors in the sequenceorder from the first address of a given VOB in accordance with thesequence order of data.

[0255] *I-picture size 1809 in corresponding VOBU

[0256] . . . As has been described above with reference to FIG. 10C orFIG. 10I, dummy information 1704 is recorded in a field which is shortfrom an integer multiple of 2,034 bytes as the pack size in the datasizes of I-pictures 1706 and 1707. Hence, when the I-picture size isknown in advance, the recording location of dummy information 1704 canbe detected, and the next location can be accessed without playing backthat location, thereby realizing high-speed playback.

[0257] *S_PTM (presentation starting time) 1810 of still picture (V_PCK& SP_PCK)

[0258] . . . This information indicates the display timing of a stillpicture and a sub-picture added thereto upon playback. In thisembodiment, a still picture recorded in V_PCK and a sub-picture to beadded to that picture are simultaneously displayed upon playback. S_PTMis used to set the display timing in relation to audio information inone VOBU.

[0259] *First-SCR (first system clock) 1811 of still picture (V_PCK)

[0260] . . . This information means the system clock value upon creatingfirst V_PCK in a VOBU upon recording on the information storage medium(optical disc 1001), and is used upon executing seamless (continuous)playback.

[0261] As information that pertains to audio information in a VOBU whichrecords one still picture information, the following information isrecorded.

[0262] *first A PCK address 1812 in VOBU

[0263] . . . Taking FIGS. 10A to 10L as an example, address data of,e.g., A_PCKs 1691, 1693, 1694, 1695, 1696, 1699, 1702, and the likelocated at the start positions of VOBUs are recorded. When the ID of aVOB that contains a still image the user wants to watch, and the stillpicture number (VOBU number) in that VOB are designated, an optical head(not shown) directly accesses the start V_PCK address of thecorresponding VOBU using this address data.

[0264] As shown in FIG. 14C, in the present invention, audio information(A_PCK information) in one VOB can be displayed in combination withstill picture information that belongs to another VOB. Hence, thisinformation is used when audio information alone in a VOB is selectivelyplayed back.

[0265] *S_PTM (presentation starting time) 1813 of audio information(A_PCK)

[0266] . . . This information indicates the output timing of audioinformation upon playback. In most cases, this value matches S_PTM 1810of a still picture (V_PCK & SP_PCK). A different value may beintentionally set when an audio is to be output a specific time (e.g.,0.5 sec) after a still picture is displayed on the screen. In thismanner, this information is used in timing control between the stillpicture display and audio information output.

[0267] *E_PTM (presentation terminating time) 1814 of audio information(A_PCK)

[0268] . . . This information indicates the output termination timing ofaudio information upon playback, and is used in timing control betweenthe still picture display and audio information output. In most cases,this value matches S_PTM 1810 (to be described below) of a still picture(V_PCK & SP_PCK). A different value may be intentionally set when thenext still picture information begins to be displayed a specific time(e.g., 0.5 sec) after termination of the audio output.

[0269] *First_SCR (first system clock reference) 1815 of audioinformation (A_(—PCK))

[0270] . . . This information indicates the system clock value uponcreating first A_PCK in a VOB upon recording on the information storagemedium (optical disc 1001), and is used upon executing seamless(continuous) playback.

[0271] *Last_SCR (last system clock reference) 1816 of audio information(A_PCK)

[0272] . . . This information indicates the system clock value uponcreating last A_PCK in a VOB upon recording on the information storagemedium (optical disc 1001), and is used upon executing seamless(continuous) playback.

[0273] The contents corresponding to A_PB_TM mentioned in thedescription of S_VOB_ENT in FIG. 12 can be expressed by a pair ofFirst_SCR and Last_SCR above.

[0274] In this manner, by recording presentation time PTM informationand system clock reference SCR information that respectively pertain tostill picture information and audio information, video information thatbelongs to video objects 1012 shown in FIG. 1D can be used as a part ofstill picture information.

[0275] More specifically, new video object information for pictureobjects (S_VOB) for a still picture is defined as follows withoutmodifying video information itself that belongs to video objects 1012.

[0276] A case will be explained below wherein still pictures that changeevery 2 sec are defined with respect to the conventional video method(video objects 1012). In general, since the time required for one GOP invideo information is 0.5 sec, one VOBU shown in FIG. 3E normally has aduration around 0.5 sec. Since 2 sec÷0.5 sec=4, the first I-pictures ofevery four VOBUs are considered as still pictures, thus settinginformation of first V_PCK address 1808 and I-picture size 1809 in aVOB, and setting the numerical values of data in the right column ofFIG. 18.

[0277] As a result, by combining and displaying still pictureinformation and audio information that belong to different VOBs (VOB#Aand VOB#B), as shown in FIGS. 14A to 14G, only an audio part in videoinformation that belongs to video objects 1012 can be output upondisplaying a still picture, or only a scene the user likes in videoinformation that belongs to video objects 1012 can be converted into astill picture and the still picture can be displayed.

[0278] A method of displaying a plurality of still pictures will beexplained below.

[0279] As a method of displaying a plurality of pieces of still pictureinformation recorded on the information storage medium (optical disc1001), a method of simultaneously displaying a plurality of pictures ina given layout (still pictures to be displayed in the given layout areoften moved or replaced), as shown in FIG. 11, and a method ofdisplaying one still picture, and changing the still picture to bedisplayed at specific time intervals are available. In either method, acell and PGC information are used in the data structure, as shown inFIGS. 6 and 7, and the user can choose the display method by aninformation recording/playback apparatus (RTR video recorder) forrecording video information shown in FIG. 19.

[0280] As in video object information 1107, cell playback information(or CI) 1108 shown in FIG. 1F is divided into cell playback information(M_CI) that pertains to video information, and cell playback information(S_CI) that pertains to still picture information. The cell playbackinformation (S_CI) that pertains to still picture information has astructure that can play back a still picture and audio information fromdifferent locations, and can present them together, as shown in FIGS.14A to 14G.

[0281] More specifically, as shown in FIGS. 14C to 14E, in thisstructure, V_PCKs 1852 and 1854, and SP_PCK 1848 used in display in agiven cell can designate still pictures (STL PCT) 1832 and 1834 in VOB#A1821, and audio information output from that cell can designate audioinformation 1845 and audio information 1846 in VOB#B 1822 different fromVOB#A 1821.

[0282] This structure is suitable for after recording setups for a stillpicture. For example, when still picture information sensed by a digitalcamera having no audio input function is directly recorded on theinformation storage medium (optical disc 1001), its recording result hasa structure that does not contain any A_PCK (audio pack), as shown inFIG. 10I. A case will be examined below wherein the recorded informationis played back, and comments are added to still pictures one by one by“audio input via a microphone”, “overwriting marks by handwriting”,“addition of text information by key-in”, and the like, while displayingthem on the screen, as shown in FIG. 11.

[0283] In this case, when the recording format is to be changed from thestructure that does not contain any A_PCK shown in FIG. 10I to astructure that contains A_PCK shown in FIG. 10F, re-recording must bedone on the information storage medium (optical disc 1001), resulting incumbersome processes and a long processing time.

[0284] By contrast, when additional information alone is recorded asanother VOB 1634 on the information storage medium (optical disc 1001),as shown in FIGS. 10J to 10L, without modifying the data that does notcontain any A_PCK (audio pack) shown in FIG. 10I, information can beadded to a still image very easily and quickly later. Upon display, VOBs1633 and 1634 in FIGS. 10G and 10J are displayed and output togetherlike VOBs 1403 to 1405 in FIG. 3D.

[0285]FIG. 15 shows the data structure in cell playback information forpicture objects (S_CI) that allows the presentation shown in FIGS. 14Ato 14G. ID information (or CI_SRP) 1873 as an identifier unique to acell is described first. Type information (or C_TY) 1880 of a celldescribed next represents:

[0286] 1) identification information for identifying cell informationthat pertains to video information (video objects 1012), cellinformation that pertains to a still picture (picture objects 1013), orcell information that pertains to only audio information (audio objects1014); and

[0287] 2) identification information for identifying cell information(corresponding to the structure shown in FIG. 15) for a VOB that recordsa plurality of still pictures (the format shown in FIGS. 10D to 10L), orcell information (corresponding to the structure shown in FIG. 16) for aVOB that records only one still picture (the format shown in FIGS. 10Ato 10C).

[0288] In this way, by absorbing any differences of the recordingformats that record still pictures at the level of cell playbackinformation for picture objects (S_CI), both still and moving picturescan be played back and displayed in a single sequence at the level ofPGC shown in FIG. 7 beyond the recording format difference of VOBs,irrespective of the still picture information and moving pictureinformation.

[0289] In the embodiment shown in FIG. 14A, VOB#A 1821 is designated asID information 1874 of a VOB shown in FIG. 15 that records a video pack.When the user wants to display still pictures from the second one inVOB#A 1821, still picture number 2 in VOB#A 1821 is designated as stillpicture number 1875 to be displayed first in a cell. Also, incorrespondence with the embodiment shown in FIG. 14B, still picturenumber h in VOB#A 1821 is designated as still picture number 1876 to bedisplayed last in the cell.

[0290] In this manner, the cell playback information for picture objects(S_CI) directly designates a “still picture” itself.

[0291] In the embodiment show in FIG. 15, “still picture number” isdesignated as a method of designating a still picture. However, thepresent invention is not limited to such specific method. For example, astill picture may be designated by “designating a unit (e.g., a VOBU)itself where a still picture is recorded”, “designating the startaddress of a location where a still picture is recorded”, “designatingthe sequence order in a VOB”, and the like. In FIG. 15, the first andlast still pictures in the cell are designated. However, in place of theabove display method, the first still picture to be displayed in a cell,and the total number of still pictures to be displayed in that cell maybe designated.

[0292] Similarly, in FIG. 15, ID information 1877 (which designatesVOB#B 1822 in the embodiment shown in FIG. 14G) of a VOB that records anaudio pack, and still picture number 1878 (which designates stillpicture number j in the embodiment shown in FIG. 14F) indicating therecording destination of the first audio information (A_PCK) to beoutput in a cell are described.

[0293] In FIG. 15, no still picture number information indicating therecording destination of the last audio information (A_PCK) to be outputin the cell is described. However, since the total number of stillpictures to be displayed in one cell can be detected based on stillpicture number 1875 that indicates the first still picture to bedisplayed in a cell, and still picture number 1876 indicating the laststill picture to be displayed in the cell, that still picture numberinformation need not be described.

[0294] When audio information is designated for all still pictures inFIG. 14C, the presentation time per still picture can be determined byS_PTM 1813 and E_PTM 1814 of audio information shown in FIG. 13. On theother hand, when no audio information is designated for a specific VOBU,the still picture presentation time is set using information ofpresentation time 1879 per still picture.

[0295] Referring to FIG. 15, 1873 to 1876 correspond to the stillpicture file (RTR_STO.VRO) in FIG. 2, and 1877 to 1879 correspond to theafter recording audio file (RTR_STA.VRO) shown in FIG. 2.

[0296] A grouping and displaying method when one VOB records only onestill picture will be explained below.

[0297] As shown in FIGS. 10A to 10C, when one VOB (video object forpicture objects) 1631 records only one still picture, a plurality ofVOBs having still pictures are grouped and that group is handled aspart_of_title. This grouping information is recorded in part_of_titlesinformation 1753 (FIG. 8) in video title set information (RTR_VMGI) 1106shown in FIG. 1F.

[0298] The data structures in part_of_titles information 1753 thatpertains to still pictures shown in FIG. 17, and VOB map 1899 forpicture objects are similar to those in video object information(S_VOGI#) shown in FIG. 12, and the VOBU map for picture objects(S_VOB_ENT#) shown in FIG. 13.

[0299] Also, the structure of the corresponding cell playbackinformation for picture objects (CI) shown in FIG. 16 is similar to thatof S_CI shown in FIG. 15.

[0300] One embodiment of an information recording/playback apparatus(RTR video recorder) for recording video information will be explainedbelow.

[0301]FIG. 19 is a block diagram for explaining the arrangement in theRTR video recorder. In this specification, reference numerals areindicated within blocks to save space.

[0302] The apparatus main body of the video recorder shown in FIG. 19 isroughly comprised of disc changer (disc drive unit) 1500 for rotatingone to be used of one or a plurality of information storage media(optical discs) 1001, and executing recording and playback of videoinformation with respect to optical disc 1001, encoder unit 1550 thatconstructs the video recording side, decoder unit 1560 that constructsthe playback side, and system controller (MPU) 1530 which incorporates aROM and RAM (semiconductor memory), and controls the operations of theapparatus main body.

[0303] Encoder unit 1550 comprises ADC (analog-to-digital converter)1552, video encoder (V encoder) 1553, audio encoder (A encoder 1554),sub-picture encoder (SP encoder) 1555, formatter 1556, and buffer memory1557.

[0304] ADC 1552 receives an external analog video signal+external analogaudio signal from AV input 1542, or analog TV signal+analog audio signalfrom TV tuner 1544. This ADC 1552 converts the input analog video signalinto digital data at, e.g., a sampling frequency=13.5 MHz and the numberof quantization bits=8. (More specifically, luminance component Y, colordifference component Cr (or Y-R), and color difference component Cb (orY-B) are respectively quantized by 8 bits.) Likewise, ADC 1552 convertsthe input analog audio signal into digital data at, e.g., a samplingfrequency=48 kHz and the number of quantization bits=16.

[0305] When an analog video signal and digital audio signal are input toADC 1552, the digital audio signal passes through ADC 1552. (A processfor reducing jitter superposed on a digital signal, a process forchanging the sampling rate and the number of quantization bits, or thelike without changing the contents of a digital audio signal may bedone.)

[0306] When a digital video signal and digital audio signal are input toADC 1552, these signals pass through ADC 1552 (for these digitalsignals, a jitter reduction process, sampling rate change process, orthe like that do not change their contents may be done).

[0307] When still picture information sensed by digital camera 1543 isinput in addition to the input video signals, it is directly input to Vencoder 1553 without the intervention of ADC 1552.

[0308] A digital video signal component output from ADC 1552 is sent toformatter 1556 via video encoder (V encoder) 1553. A digital audiosignal component output from ADC 1552 is sent to formatter 1556 viaaudio encoder (A encoder) 1554. Or a still picture signal directly inputto V encoder 1553 is sent from V encoder 1553 to formatter 1556.

[0309] V encoder 1553 has a function of converting the input digitalvideo signal into a digital signal compressed at variable bit rate onthe basis of the MPEG2 or MPEG1 specifications.

[0310] In digital camera 1543, still picture information is recorded inthe bitmap or JPEG format. By contrast, in the present invention, astill picture is recorded on optical disc 1001 in the I-picture formatof MPEG2. For this purpose, in the present invention, V encoder 1553 hasformat conversion functions of “bitmap→MPEG2”, “JPEG→MPEG2”, and thelike.

[0311] A encoder 1554 has a function of converting the input digitalaudio signal into a digital signal (or linear PCM digital signal)compressed at fixed bit rate on the basis of the MPEG or AC-3specifications.

[0312] When a digital video signal (for example, a signal from a DVDvideo player with an independent output terminal of a sub-picturesignal) is input from AV input 1542, or when a DVD video signal withsuch data structure is broadcasted and is received by TV tuner 1544, thesub-picture signal component (sub-picture pack) in the video signal isinput to sub-picture encoder (SP encoder) 1555. Sub-picture data inputto SP encoder 1555 is arranged into a predetermined signal format, andis then sent to formatter 1556.

[0313] Formatter 1556 executes predetermined signal processing of theinput video signal, audio signal, sub-picture signal, and the like usingbuffer memory 1557 as a work area, and outputs recording data thatmatches a predetermined format (file structure) to data processor 1536.

[0314] In case of digital broadcast, a video signal is transmitted inthe TS (transport stream) format of MPEG2. In general, when a videosignal is recorded on information storage medium (optical disc) 1001 inthe MPEG2 format, the PS (program stream) format is used. Hence, uponreceiving digital broadcast, the received signal is directly sent fromTV tuner 1544 to formatter 1556, which executes “TS→PS conversion”.

[0315] Standard encode process contents for creating the recording datawill be briefly explained below. More specifically, when encoder unit1550 shown in FIG. 19 starts an encode process, parameters required forencoding video (main picture) data and audio data are set. Main picturedata is pre-encoded using the set parameters, and optimal code amountdistribution for the selected average transfer rate (recording rate) iscalculated. Then, the main picture data is encoded based on the codeamount distribution obtained by pre-encoding. At this time, audio datais encoded simultaneously.

[0316] As a result of pre-encoding, if it is determined that the datacompression amount is insufficient (a desired video program cannot fallwithin information storage medium (optical disc) 1001 to be used), andpre-encoding can be re-done (if the source to be recorded is a sourcethat can be repetitively played back such as a video tape, video disc,or the like), main picture data is partially re-encoded, and thepreviously pre-encoded main picture data portion is replaced by there-encoded main picture data portion. With a series of processesdescribed above, the main picture and audio data are encoded, and theaverage bit rate value required for recording can be greatly reduced.

[0317] Likewise, parameters required for encoding sub-picture data areset, and encoded sub-picture data is generated.

[0318] The encoded main picture, audio, and sub-picture data arecombined, and are converted into the data structure of desired videoobjects.

[0319] More specifically, a cell as a minimum unit of main picture data(video data) is set, the configuration of cells that form a programchain, attributes of the main picture, sub-picture, and audio data, andthe like are set (some of such attribute data use information obtainedupon encoding the respective data), and management information thatcontains various kinds of information which pertain to cells is recordedin the management information recording area (control information 1011in FIG. 1D or RTR.IFO in FIG. 2).

[0320] The encoded main picture, audio, and sub-picture data aresegmented into packs each having a predetermined size (2,048 bytes).Dummy packs that can be used in, e.g., after recording, are insertedinto these packs as needed. Note that time stamps such as PTS(presentation time stamp), DTS (decode time stamp), and the like aredescribed in packs other than dummy packs, as needed. As for PTS ofsub-picture data, a time arbitrarily delayed from PTS of main picturedata or audio data in the identical playback time band can be described.

[0321] Data cells are arranged in units of VOBUs to allow playback inthe time code order of data, thus forming a VOB consisting of aplurality of cells.

[0322] Upon digitally copying video information from the digital outputof the RTR video recorder shown in FIG. 19, since the contents of thecells, program chains, management tables, time stamps, and the like aredetermined in advance, they need not be created again.

[0323] The arrangement for reading/writing (recording and/or playingback) information from/to optical disc 1001 comprises disc drive unit(disc changer) 1500, information recording/reproducing unit 101,temporary buffer memory 1534, data processor 1536, and system timecounter (or system time clock; STC) 1538.

[0324] Temporary buffer memory 1534 is used to buffer a given amount ofdata to be written on optical disc 1001 (data output from encoder unit1550) via information recording/reproducing unit 101, and to buffer agiven amount of data played back from optical disc 1001 (data input todecoder unit 1560) via information recording/reproducing unit 101.

[0325] For example, when temporary buffer memory 1534 comprises a4-Mbyte semiconductor memory (DRAM), it can buffer recording or playbackdata for approximately 8 seconds at an average recording rate of 4 Mbps.When temporary buffer memory 1534 comprises a 16-Mbyte EEPROM (flashmemory), it can buffer recording or playback data for approximately 30seconds at an average recording rate of 4 Mbps. Furthermore, whentemporary buffer memory 1534 comprises a 100-Mbyte, very small HDD (harddisc drive), it can buffer recording or playback data for 3 minutes ormore at an average recording rate of 4 Mbps.

[0326] Also, temporary buffer memory 1534 can also be used totemporarily store recording information when optical disc 1001 is usedup during video recording, until optical disc 1001 is exchanged by a newdisc.

[0327] When information recording/reproducing unit 101 uses a high-speedrecording/reproducing unit having a speed equal to or higher than doublespeeds, temporary buffer memory 1534 can also be used to store readoutdata exceeding a normal amount read out from the drive per unit time.When temporary buffer memory 1534 buffers readout data upon playback,even when an optical head (not shown) has caused read errors due tovibration shock or the like, playback data buffered by temporary buffermemory 1534 can be used instead, thus preventing a playback image frombeing discontinued.

[0328] If an external card slot (not shown in FIG. 19) is provided tothe RTR video recorder, the EEPROM can be offered as an option IC card.On the other hand, if an external drive slot or SCSI interface isprovided to the RTR video recorder, the HDD can be offered as an optionextension drive.

[0329] When a personal computer is used as a DVD video recorder bysoftware, the free area of a hard disc drive or main memory of thepersonal computer itself can be used as temporary buffer memory 1534shown in FIG. 19.

[0330] Under the control of system controller (MPU) [incorporating theROM and RAM] 1530, data processor 1536 shown in FIG. 19 performs:

[0331] supply of a video information signal to be recorded from encoderunit 1550 to information recording/reproducing unit 101;

[0332] transfer of a video information signal played back by informationrecording/reproducing unit 101 to another unit;

[0333] rewrite of management information (control information 1011)recorded on information storage medium (optical disc) 1001;

[0334] partial deletion of video information and management information(control information 1011 or RTR.IFO or RTR_VMG) as data recorded oninformation storage medium (optical disc) 1001; and the like.

[0335] System controller 1530 includes an MPU (or CPU), a ROM as an ICmemory written with control programs and the like, and a RAM as an ICmemory that provides a work area required for executing programs.

[0336] Of the execution results of system controller 1530, the contentsthe user of the RTR video recorder should know are displayed ondisplay/input panel 1548 of the RTR video recorder.

[0337] Note that the control timings of disc changer 1500, informationrecording/reproducing unit 101, data processor 1536, and encoder unit1550 and/or decoder unit 1560 by system controller (MPU) 1530 can bedetermined based on time data supplied from STC 1538 (videorecording/playback are normally executed in synchronism with time clocksfrom STC 1538, but other processes may be executed at timingsindependently of STC 1538).

[0338] Decoder unit 1560 comprises separator 1562 for separating therespective packs from video information with the pack structure recordedon optical disc 1001, memory 1563 used upon executing pack separationand other signal processes, video decoder (V decoder) 1564 for decodingmain picture data (the contents of video packs) separated by separator1562, sub-picture decoder (SP decoder) 1565 for decoding sub-picturedata (the contents of sub-picture packs) separated by separator 1562,audio decoder (A decoder) 1568 for decoding audio data (the contents ofaudio packs) separated by separator 1562, video processor 1566 forappropriately mixing sub-picture data from SP decoder 1565 with videodata output from V decoder 1564, i.e., superposing sub-picture data suchas menus, highlight buttons, superimposed dialogs, and the like on mainpicture data, and outputting them, video digital-to-analog converter(V•DAC) 1567 for converting the digital video output from videoprocessor 1565 into an analog video signal, and audio digital-to-analogconverter (A•DAC) 1569 for converting the digital audio output from Adecoder 1568 into an analog audio signal.

[0339] The analog video signal (analog video information signal) outputfrom V•DAC 1567, and the analog audio signal output from A•DAC 1569 aresupplied to an external component (not shown; a multi-channel stereosystem having two to six channels+monitor TV or projector) via AV output1546.

[0340] OSD (On Screen Display) data output from system controller (MPU)1530 is input to separator 1562 in decoder unit 1560, and is then inputto video processor 1566 via V decoder 1564 (not decoded). The OSD datais superimposed on main picture data, and they are supplied to anexternal monitor TV connected to AV output 1546. Thus, a warning messageis displayed together with main picture data.

[0341] The operations of the information recording/playback apparatus(RTR video recorder) for recording video information shown in FIG. 19will be described below with reference to the flow charts.

[0342] The sequence for recording a plurality of still pictures oninformation storage medium (optical disc) 1001 will be described belowwith reference to FIG. 20.

[0343] Still picture files are continuously input from digital camera1543 as data (ST1).

[0344] Since each still picture file received from digital camera 1543is normally recorded in the JPEG or bitmap format, the input stillpicture information is converted into I-picture data of MPEG2 at Vencoder 1553 (ST2).

[0345] Formatter 1556 prepares the VOBU structure with the datastructure shown in FIG. 3 with respect to single still pictureinformation, and groups a plurality of still pictures to construct a VOB(ST3).

[0346] Parallel to the aforementioned processes, informationrecording/reproducing unit 101 reproduces all pieces of controlinformation 1011 (RTR.IFO/RTR_VMG) recorded on optical disc 1001, andsaves the reproduced contents in the internal RAM of system controller1530 (ST4).

[0347] System controller 1530 obtains information of allocation maptable 1105 from the contents of control information 1011 saved in itsinternal RAM, and searches for the location of unrecorded area 1460(FIG. 4) (ST5).

[0348] After that, system controller 1530 sends control information toformatter 1556, data processor 1536, and informationrecording/reproducing unit 101, and controls informationrecording/reproducing unit 101 to record a VOB having a plurality ofpieces of still picture information on unrecorded area 1460 (ST6).

[0349] During recording, system controller 1530 monitors the recordingstate, and checks if the VOB is successfully recorded on optical disc1001 (ST7). If trouble has occurred during recording, the processes insteps ST4 to ST6 are repeated.

[0350] If the VOB is successfully recorded on optical disc 1001, systemcontroller 1530 prepares VOBU map 1738 in FIG. 12 (or VOB map 1899 inFIG. 17) on the basis of address information recorded on optical disc1001 (ST9). Finally, VOBU map 1738 (or VOB map 1899) prepared in systemcontroller 1530 is additionally recorded in control information 1011(RTR.IFO/RTR_VMG) on optical disc 1001 using informationrecording/reproducing unit 101 (ST10).

[0351] The playback sequence of still picture information containingaudio information will be described below with the aid of FIG. 22.

[0352] As in steps ST4 and ST5 in FIG. 20, informationrecording/reproducing unit 101 reproduces all pieces of controlinformation 1011 (RTR.IFO/RTR_VMG) recorded on optical disc 1001, andsaves the reproduced contents in the internal RAM of system controller1530 (ST11).

[0353] System controller 1530 obtains information of playback controlinformation 1021 (CI) from the contents of control information 1011saved in its internal RAM, and interprets the obtained information as tothe manner of reproduction (ST12).

[0354] After that, system controller 1530 searches for a program ofinformation to be reproduced from PGC control information 1103 (PGCI)saved in its internal RAM, and extracts a cell or cells contained inthat PGC information (ST13).

[0355] Furthermore, system controller 1530 extracts the recordingaddress of the VOB to be reproduced on optical disc 1001 from videoobject information 1107 (AVFIT) or part_of_titles information 1753 (FIG.8) in video title set information 1106 (RTR_VMGI) saved in its internalRAM (ST14).

[0356] The playback sequence for playing back still picture informationfrom VOB#A and presenting audio information recorded in VOB#Bsimultaneously with the still picture upon playback, as shown in FIGS.14A to 14G, will be explained.

[0357] An optical head (not shown) in information recording/reproducingunit 101 accesses VOB#B recorded on optical disc 1001 on the basis of acontrol signal from system controller 1530 to reproduce its information,and temporarily saves audio information for a plurality of stillpictures in that reproduced information in memory 1563 (FIG. 19) (ST18).

[0358] The optical head in information recording/reproducing unit 101then accesses the information recording position of VOB#A recorded onoptical disc 1001 to reproduce still picture information in VOB#A(ST16). Finally, AV output 1546 simultaneously outputs (displays) audioinformation in VOB#B and still picture information in VOB#A (ST17).

[0359] As described above, the method of simultaneously reproducing onlyaudio information for a plurality of still pictures or only stillpicture information, saving the reproduction result in memory 1562,simultaneously reproducing the remaining information, and outputting(displaying) the reproduction results at the same time is used. Withthis method, compared to a method of reproducing still pictureinformation and audio information in units of still pictures, thefrequency of access of the optical head can be greatly reduced, thusallowing a seamless, continuous output (free from any wait time uponchanging the still picture to be displayed, or free from any interruptof audio information). This is a great feature of this invention.

[0360] In FIG. 22 described above, after audio information in VOB#B isreproduced, still picture information in VOB#A is reproduced. However, amodification may be made without departing from the scope of the presentinvention (e.g., the reproduction order may be replaced).

[0361] In the recording format shown in FIGS. 10A to 10L, a pair ofstill picture information and audio information are saved in a VOBU.However, the present invention is not limited to such specific format.The contents of the present invention can be applied as long as thescope of the invention is implemented.

[0362] For example, in case of a recording format in which V_PCKs for aplurality of still pictures may be allocated in one VOB or in the firsthalf of one PTT, and A_PCKs for a plurality of still pictures areallocated in the second half, the positions of V_PCK and A_PCK of astill image of a given number are separated from each other oninformation storage medium (optical disc) 1001. Hence, even when stillpicture information (V_PCK information) and audio information (A_PCKinformation) with an identical still picture number in one VOB arereproduced in turn, optical head access is required.

[0363] Therefore, when a plurality of pieces of still pictureinformation are reproduced from picture objects 1013 with the recordingformat in which V_PCKs for a plurality of still pictures may beallocated in one VOB or in the first half of one PTT, and A_PCKs for aplurality of still pictures are allocated in the second half, eitherV_PCK or A_PCK information for a plurality of still pictures is read inadvance and saved in memory 1563, the remaining information is thenreproduced, and the reproduction results can be simultaneously output(displayed), according to the sequence of the present invention.

[0364] As another embodiment of the present invention, a method ofadditionally recording additional information for a still picture byafter recording will be explained below with reference to FIG. 21.Information to be added by after recording forms a group (another VOB orPTT) different from that of original still picture information, and theadditional information and still picture information are synthesized andoutput (displayed) by the method shown in FIGS. 14A to 14G.

[0365] Referring to FIG. 21, steps ST11 to ST14 are the same as those inFIG. 22. The optical head in information recording/reproducing unit 101accesses a VOB recorded on optical disc 1001 to reproduce itsinformation, and the display contents shown in FIG. 11 are supplied toAV output 1546 (ST18). Additional information input by the user whileobserving the display screen is received, and a plurality of stillpictures are grouped by formatter 1556 on the basis of the inputinformation to construct a VOB or PTT (ST19).

[0366] Finally, VOB information constructed by formatter 1556 isrecorded on optical disc 1001 (ST20).

[0367]FIG. 23 is a view for explaining the data structure of navigationdata (RTR_VMG) shown in FIG. 8. This RTR_VMG corresponds to controlinformation 1101 and information 1021 in FIG. 1E, and corresponds tocontrol information (RTR.IFO) 1011 in the file structure shown in FIG.2.

[0368] Of this navigation data RTR_VMG, user defined PGC informationtable UD_PGCIT is comprised of user defined PGC information tableinformation (UD_PGCITI), one or more user defined PGC information searchpointers #1 to #n (UD_PGCI_SRP#1 to UD_PGCI_SRP#n), and one or morepieces of user defined PGC information #1 to #n (UD PGCI#1 to UD_PGCI#n)corresponding in number to these search pointers.

[0369] Each user defined PGC information (one of UD_PGCI#1 to UD_PGCI#n)or PGC information #i (PGCI#i) having contents corresponding to originalPGC information (ORG_PGCI) is composed of PGC general information(PGC_GI), one or more pieces of program information #1 to #m (PGI#1 toPGI#m), one or more cell information search pointers #1 to #n (CI_SRP#1to CI_SRP#n), and one or more pieces of cell information #1 to #n (CI#1to CI#n) corresponding in number to these search pointers.

[0370] Each cell information search pointer (one of CI_SRP#1 toCI_SRP#n) contains the start address (CI_SA) of corresponding cellinformation, and each cell information (one of CI#1 to CI#n) containsmovie cell information (M_CI) or still picture cell information (S_CI).

[0371] Note that RTR_VMGI in FIG. 23 corresponds to video title setinformation 1106 in FIG. 1F, M_AVFIT and S_AVFIT in FIG. 23 correspondto video object information 1107 in FIG. 1F, and ORG_PGCI and UD_PGCITin FIG. 23 correspond to PGC control information 1103 in FIG. 1F.

[0372] On the other hand, PGCI#i in FIG. 23 corresponds to PGC controlinformation 1103 in FIG. 1F, and CI# in FIG. 23 corresponds to cellplayback information 1108 in FIG. 1F.

[0373]FIG. 24 is a view for explaining the contents of still picturecell information (S_CI) in FIG. 23. S_CI contains still picture cellgeneral information (S_C_GI), and one or more pieces of still picturecell entry point information #1 to #n (S_C_EPI#1 to S_C_EPI#n). Notethat S_CI in FIG. 24 corresponds to cell playback information 1108 inFIG. 1F.

[0374]FIG. 25 is a view for explaining the contents of still picturecell general information (S_C_GI) in FIG. 24.

[0375] This S_C_GI contains a cell type (C_TY) which describes the typeof cell, the still picture VOB group information search pointer number(S_VOGI_SRPN) of the VOB group used by this cell, the number (C_EPI_Ns)of pieces of cell entry point information in this cell, the startaddress (S_S_VOB_ENTN) of the still picture VOB entry number of thiscell, and the end address (E_S_VOB_ENTN) of the still picture VOB entrynumber of this cell.

[0376] Note that S_S_VOB_ENTN in FIG. 25 corresponds to still picturenumber 1875 in VOB in FIG. 15, and E_S_VOB_ENTN in FIG. 25 correspondsto still picture number 1876 in a VOB in FIG. 15.

[0377]FIG. 26 is a view for explaining the contents of each stillpicture cell entry point information (S_C_EPI) in FIG. 24. This S_C_EPIhas two different types (type 1 and type 2).

[0378] S_C_EPI of type 1 contains an entry point type (EP_TY) thatdescribes the type of entry point, and still picture VOB entry number(S_VOB_ENTN).

[0379] S_C_EPI of type 2 further contains primary text information(PRM_TXTI) in addition to EP_TY and S_VOB_ENTN. This PRM_TXTI can recorda comment and other information associated with the corresponding stillpicture.

[0380] Note that S_VOB_ENTN in FIG. 26 is number information whichspecifies each of one or more still picture VOB entries S_VOB_ENT#(corresponding to VOBU map 1738 for picture objects in FIGS. 12 and 13,or VOB map 1899 for picture objects in FIG. 17).

[0381]FIG. 27 is a view for explaining the contents of still pictureadditional audio file information (S_AAFI) in FIG. 12.

[0382] This S_AAFI contains still picture additional audio fileinformation general information (S_AAFI_GI), one or more still pictureadditional audio group information search pointers #1 to #n(S_AAGI_SRP#1 to S_AAGI_SRP#n), and a plurality of pieces of stillpicture additional audio group information #1 to #n (S_AAGI#1 toS_AAGI#n) corresponding in number to these search pointers.

[0383] Each still picture additional audio group information (one ofS_AAGI#1 to S_AAGI#n) contains still picture additional audio groupgeneral information (S_AAG_GI), and one or more additional audio entries#1 to #n (AA_ENT#1 to AA_ENT#n).

[0384]FIG. 28 is a view for explaining the contents of S_AA_GI generalinformation (S_AAG_GI) in FIG. 27.

[0385] This S_AAG_GI contains the number (AA_ENT_Ns) of additional audioentries, the still picture additional audio stream information number(S_AA_STIN), and the start address (S_AA_SA) of AAG in a still pictureadditional audio file.

[0386] Note that AA_ENT_Ns in FIG. 28 assumes a value corresponding tonumber 1801 of still pictures in a VOB in FIG. 13 or number 1901 ofstill pictures in PTT in FIG. 18.

[0387] S_AA_SA in FIG. 28 corresponds to the first still picture address(first still picture information 1802 in a VOB or first V_PCK address1808 in a VOBU in FIG. 13; or first still picture information 1902 in aPTT or first V_PCK address 1908 in a VOB in FIG. 18).

[0388]FIG. 29 is a view for explaining the contents of the additionalaudio entry (AA_ENT) shown in FIG. 27.

[0389] This AA_ENT contains an additional audio type (AA_TY) thatdescribes the type of additional audio (e.g., normal one or tentativelycreated one), the size (AA_SZ) of an additional audio stream, and theplayback time (AA_PB_TM) of the additional audio stream.

[0390] Note that AA_SZ in FIG. 29 assumes a value corresponding to thedifference between the A_PCK address of the current additional audio(first A_PCK address 1812 in a VOBU in FIG. 13 or first A_PCK address1912 in a VOB in FIG. 18), and the A_PCK address of the next additionalaudio (1812 in FIG. 13 or 1912 in FIG. 18).

[0391] On the other hand, AA_PB_TM in FIG. 29 corresponds to thedifference obtained by subtracting audio S_PTM 1813 from audio E_PTM1814 in FIG. 13 (or the difference obtained by subtracting audio S_PTM1913 from audio E_PTM 1914 in FIG. 18).

[0392]FIG. 30 is a view for explaining the contents of still picture VOBgroup general information (S_VOG_GI) shown in FIG. 12.

[0393] This S_VOG_GI contains the number (S_VOB_Ns) of still picturesthat describes the number of video parts in the corresponding VOB group,the number (S_VOB_STIN) of pieces of still picture VOB streaminformation, the time (FIRST_VOB_REC_TM) when the first VOB in that VOBgroup was recorded, the time (LAST_VOB_REC_TM) when the last VOB in thatVOB group was recorded, and the start address (S_VOG_SA) of that VOBgroup in a still picture AV file.

[0394] Note that S_VOB_Ns in FIG. 30 has a value corresponding to number1901 of still pictures in a VOB in FIG. 13 or number 1901 of stillpictures in a PTT shown in FIG. 18.

[0395] Also, S_VOG_SA in FIG. 30 corresponds to the first still pictureaddress (first still picture information 1802 in a VOB or first V_PCKaddress 1808 in a VOBU in FIG. 13; or first still picture information1902 in a PTT or first V_PCK address 1908 in a VOB in FIG. 18).

[0396]FIG. 31 is a view for explaining the first example (type 1) of thecontents of still picture VOB entry (S_VOB_ENT) in FIG. 12.

[0397] This S_VOB_ENT of type 1 contains a still picture VOB entry type(S_VOB_ENT_TY) that describes the type of still picture VOB entry, andthe size (V_PART_SZ) of the corresponding still picture video part.

[0398] Note that S_VOB_ENT_TY contains information MAP_TY that describesthe type of S_VOB_ENT, information TE that describes whether thecorresponding VOB is normal or tentatively erased (temporarily erased),and information SPST_Ns that describes the number of sub-picture streamscontained (if it is zero, no streams are contained).

[0399] On the other hand, V_PART_SZ describes the size of the video partin that VOB in units of sectors.

[0400] This V_PART_SZ corresponds to the difference between the address(1808 in FIG. 13) of the first V_PCK in the current still picture VOBU,and the address (1812 in FIG. 13) of the first A_PCK in the currentstill picture VOBU.

[0401] Or this V_PART_SZ corresponds to the difference between theaddress (1908 in FIG. 18) of the first V_PCK in the current stillpicture VOB, and the address (1912 in FIG. 18) of the first A_PCK in thecurrent still picture VOB.

[0402]FIG. 32 is a view for explaining the second example (type 2) ofthe contents of still picture VOB entry (S_VOB_ENT) in FIG. 12.

[0403] This S_VOB_ENT of type 2 contains A_PART_SZ that indicates thesize of the audio part which is originally attached to the still pictureVOB in units of sectors, and A_PB_TM that indicates the playback time ofthe audio part in units of video fields, in addition to S_VOB_ENT_TY andV_PART_SZ of type 1 shown in FIG. 31.

[0404] When the playback time of an actual audio part does not match aboundary of video fields, data after the video field of end data of theaudio part is discarded.

[0405] Note that A_PART_SZ corresponds to the difference between thefirst A_PCK address (1812 in FIG. 13) in the current VOBU, and the firstV_PCK address (1808 in FIG. 13) in the next VOBU.

[0406] Or A_PART_SZ corresponds to the difference between the firstA_PCK address (1912 in FIG. 18) in the current VOB, and the first V_PCKaddress (1908 in FIG. 18) in the next VOB.

[0407] On the other hand, A_PB_TM corresponds to the difference betweencurrent S_PTM 1810; FIG. 13 (or current S_PTM 1910; FIG. 18), and nextS_PTM 1810; FIG. 13 (or next S_PTM 1910; FIG. 18).

[0408] Or A_PB_TM corresponds to the difference between S_PTM 1813 andE_PTM 1814 in FIG. 13 (or the difference between S_PTM 1913 and E_PTM1914 in FIG. 18).

[0409]FIG. 33 is a view for explaining the third example (type 3) of thecontents of still picture VOB entry (S_VOB_ENT) in FIG. 12.

[0410] This S_VOB_ENT of type 3 contains the still picture additionalaudio group number (S_AAGN) and additional audio entry number (AA_ENTN)in addition to S_VOB_ENT_TY and V_PART_SZ of type 1 shown in FIG. 31.

[0411] Note that S_AAGN indicates the number of additional audio groupthat contains the additional audio stream of the corresponding VOB. ThisS_AAGN corresponds to ID information 1877 of a VOB having A_PCK in FIG.15.

[0412] On the other hand, AA_ENTN indicates the number of additionalaudio entry corresponding to the additional audio stream of thecorresponding VOB. This AA_ENTN corresponds to still picture number 1878in a VOB that contains A_PCK of the first still picture in a cell inFIG. 15.

[0413]FIG. 34 is a view for explaining the fourth example (type 4) ofthe contents of still picture VOB entry (S_VOB_ENT) in FIG. 12.

[0414] This S_VOB_ENT of type 4 has contents that combine S_VOB_ENT_TYand V_PART_SZ of type 1 shown in FIG. 31, A_PART_SZ and A_PB_TM of type2 shown in FIG. 32, and S_AAGN and AA_ENTN of type 3 shown in FIG. 33.

[0415] In entries S_VOB_ENT of types 1 to 4 shown in FIGS. 31 to 34, thesame field names (S_VOB_ENT_TY and the like) have the same contents.

[0416]FIG. 35 is a view for explaining the relationship between theoriginal PGC information (ORG_PGCI in FIG. 8 or 23) and still picturevideo file (RTR_STO.VRO in FIG. 2) when only still picture VOBs arerecorded.

[0417] In an original PGC where only still picture VOBs are recorded,the PGCI consists of a sequence of cells, and each cell corresponds to astill picture VOB group. Still picture VOB group is introduced to reducethe navigation data size associated with each still picture VOB,considering when a huge number of still picture VOBs are recorded.However, a cell is unable to refer to both movie VOB and still pictureVOB at the same time. Therefore, if a movie VOB and a still picture VOBis recorded alternatively, a still picture VOB group may contain onlyone still picture VOB.

[0418] Assume that still picture VOB group information S_VOGI#2 in FIG.35 corresponds to VOBs 1631 to 1633 in FIGS. 10A to 10L.

[0419] Under this assumption, for example, VOBU 1641 in FIG. 10B, VOBU1644 in FIG. 10E, and VOBU 1646 in FIG. 10H are contained in S_VOGI#2.The video part in still picture VOB group #2 in FIG. 35 corresponds topacks 1661 to 1663 and 1681 in FIG. 10C, pack 1665 in FIG. 10F, or packs1668 to 1670 and 1683 in FIG. 10I.

[0420] Also, assume that S_VOGI#2 in FIG. 35 corresponds to VOB#A inFIG. 14A.

[0421] Under this assumption, for example, still picture number 2 ofVOBU 1862 in FIG. 14B corresponds to VOB entry number 2 of S_VOGI#2,packs 1852, 1848, and 1862 of still picture 1832 in FIG. 14C correspondto central video and audio parts of the RTR_STO.VRO file in FIG. 35, andpack 1853 of still picture 1833 in FIG. 14C corresponds to a trailingvideo part of the RTR_STO.VRO file.

[0422]FIG. 36 is a view for explaining the relationship between theoriginal PGC information (ORG_PGCI) and still picture additional audiopart (RTR_STA.VRO in FIG. 2).

[0423] VOB entry contains access information to the associated videopart and the audio part both of which are recorded in the RTR_STO.VROfile. The audio part is recorded immediately after the associated videopart. When an additional audio part associated with a video part isrecorded in RTR_STA.VRO file, an additional audio entry is described indata fields other than the VOGI, and a link from the VOB entry to theadditional audio entry is described in the VOB entry.

[0424] Assume that additional audio file RTR_STA.VRO in FIG. 36corresponds to VOB#B in FIG. 14G.

[0425] Under this assumption, for example, the arrow from A_PCKs 1865and 1866 in FIG. 14D to A_PCKs 1865 and 1866 in FIG. 14E corresponds tothat from a VOB entry in S_VOGI#2 in FIG. 36 to its right neighboringadditional audio entry.

[0426] In this case, paying attention to the arrow of A_PCK 1866, A_PCK1866 in FIG. 14E corresponds to the central audio part of RTR_STA.VRO inFIG. 36, and still picture number h+j−2 in FIG. 14F constructs a partcorresponding to A_PCK 1866 of the additional audio entry in FIG. 36.

[0427] The information parts (the VOB entry and additional audio entryin FIG. 36) connected by the arrow can be linked using cell playbackinformation 1108 in FIG. 1F or S_CI in FIG. 24.

[0428] When the central audio part in the RTR_STA.VRO file in FIG. 36 isaudio information of after recording, A_PCK 1866 in FIG. 14Ecorresponding to this audio part can be constructed using dummy packDM_PCK shown in FIG. 3F.

[0429]FIG. 37 is a view for explaining an example of the structure oforiginal PGC information (ORG_PGCI in FIG. 8 or 23) that contains stillpicture VOBs (RTR_STO.VRO file) and movie VOBs (RTR_MOV.VRO file).

[0430] Assume that program #1 of PGCI#1 in FIG. 37 corresponds to VTS1762 in FIG. 9E, S_VOGI#1 and S_VOGI#2 correspond to VOB#D 1774 andVOB#E 1775 in FIG. 9F, and M_VOBI#1 and M_VOBI#2 correspond to VOB#A1771 and VOB#B 1772 in FIG. 9F.

[0431] Under this assumption, picture object 1013 in FIG. 9F constructsthe contents (video and audio parts) of the RTR_STO.VRO file in FIG. 37,and video object 1012 in FIG. 9F constructs the contents (VOB#1, VOB#2,. . . ) of the RTR_MOV.VRO file in FIG. 37.

[0432] Referring to FIG. 37, cell# in PGCI and VOB entries in S_VOGI#can be linked using, e.g., S_S_VOB_ENTN and E_S_VOB_ENTN in FIG. 25.

[0433] On the other hand, the logical addresses of the video or audiopart in the RTR_STO.VRO file, and VOB numbers designated by VOB entriesin S_VOGI# can be linked using the relationships shown in, e.g., FIGS. 4and 5.

[0434] Time map TMAP in M_VOBI# in FIG. 37 will be explained below.

[0435] Movie AV file information table M_AVFIT in FIG. 8 or 23 containsmovie AV file information general information (M_AVFI_GI), one or moremovie VOB information search pointers (M_VOBI_SRP#1 to M_VOBI_SRP#n),and one or more pieces of movie VOB information (M_VOBI#1 to M_VOBI#n)corresponding in number to these search pointers (not shown).

[0436] Each M_VOBI# contains movie VOB general information (M_VOBI_GI),seamless information (SMLI), audio gap information (AGAPI), and time mapinformation (TMAPI) (not shown).

[0437] This TMAPI is used upon executing special playback (e.g., cellplayback in the order unique to the user using user defined PGC) andtime search.

[0438] TMAPI contains time map general information (TMAP_GI), one ormore time entries (TMENT#1 to TM_ENT#r), and one or more VOBU entries(VOBU_ENT#1 to VOBU_ENT#q) (not shown).

[0439] Each VOBU entry contains information that pertains to the sizeand playback time of each VOBU. The VOBU size is indicated in units ofsectors (2 kbytes or 2,048 bytes), and the playback time is indicated inunits of video fields (1/60 sec per field in NTSC; 1/50 sec per field inPAL).

[0440] Since the VOBU size is indicated in units of sectors, asdescribed above, each VOBU can be accessed using an address in units ofsectors.

[0441] Each VOBU entry contains reference picture size information1STREF_SZ, VOBU playback time information VOBU_PB_TM, and VOBU sizeinformation VOBU_SZ (not shown).

[0442] Note that VOBU_PB_TM expresses the playback time of the VOBU ofinterest in units of video fields. On the other hand, reference picturesize information 1STREF_SZ expresses the size of the first referencepicture (corresponding to I-picture of MPEG) of that VOBU in units ofsectors.

[0443] On the other hand, each time entry contains address information(VOBU_ADR) of the corresponding VOBU, and time difference information(TM_DIFF) (not shown). This time difference information indicates thedifference between the playback time designated by a time entry, and theplayback start time of the VOBU.

[0444] Assuming that the time interval (time unit TMU) between twosuccessive time entries is 10 sec, this time entry interval correspondsto, e.g., 600 fields in NTSC video.

[0445] Normally, the “time interval between neighboring VOBUs” isexpressed by the number of fields in the VOBU entry. As another method,“count value from a given VOBU to the next VOBU by a clock counter” maybe used to express the “time interval between neighboring VOBUs”.

[0446] For example, the “time interval between neighboring VOBUs” can beexpressed by the “difference value between the value of presentationtime stamp PTS at the start position of one VOBU and the value of PTS atthe start position of the immediately succeeding VOBU”.

[0447] In other words, “the time interval in a specific unit can beexpressed by the difference value of the clock counter in that unit”.

[0448] Time map generation information TMAP_GI includes TM_ENT_Nsindicating the number of time entries in that time map information,VOBU_ENT_Ns indicating the number of VOBU entries in that time mapinformation, time offset TM_OSF for that time map information, andaddress offset ADR_OFS of that time map information (not shown).

[0449] When a value (10 seconds or equivalent) corresponding to 600fields in NTSC video (or 500 fields in PAL video) is used as time unitTMU, time offset TM_OSF is used to represent the time offset within TMU.

[0450] When the VOBU size is expressed by the number of sectors, addressoffset ADR_OFS is used to indicate a file pointer from the beginning ofan AV file.

[0451] Time entry TM_ENT includes VOBU_ENTN indicating the number of thecorresponding VOBU entry, TM_DIFF indicating the time difference betweenthe playback start time of VOBU designated by the time entry, and thecalculated playback time, and VOBU_ADR indicating the target VOBUaddress (not shown).

[0452] When time unit TMU is expressed by 600 fields in NTSC (or whentime unit TMU is expressed by 500 fields in PAL), the “calculatedplayback time” with respect to time entry #j is given by TMU×(j−1)+TM_OSF.

[0453] On the other hand, VOBU_ADR indicates the target VOBU address bythe total size of VOBUs preceding the VOBU of interest when the VOBUsize is expressed in units of sectors.

[0454] In the aforementioned data structure, in order to start playbackfrom the middle of a certain VOBU, that access point must be determined.This access point is assumed to be a time entry point.

[0455] This time entry point is located at a position separated from theposition indicated by movie address information of the VOBU by the timedifference indicated by time difference information TM_DIFF in timeentry TM_ENT. This time entry point serves as a special presentationstart point (or time search point) indicated by time map informationTMAPI.

[0456] Cell# in PGCI in FIG. 37 and time map TMAP in M_VOBI# can belinked in the same manner as S_VOGI#.

[0457]FIG. 37 illustrates a case that a video field corresponding to thepresentation start time is in the middle of VOBU#k. In order to displaya sequence of video fields from a video field specified by thepresentation start time, the VOBU data from the beginning need to beinput to the decoder. This is because the decoder need to decode all ofthe reference video fields which have presentation time earlier than thepresentation start time, although the decoded fields should not bedisplayed. When the decoding reaches to the video field corresponding tothe presentation start time, the decoder should start display of thevideo pictures. This capability to start display exactly at the videofield corresponding to the presentation start time is recommended.

[0458]FIG. 38 is a view for explaining a case wherein user defined PGCInformation (FIG. 6) refers to a still picture VOB group.

[0459] A user defined PGC may include two types of cells, each of whichrefers to a movie VOB or a still picture VOB group, respectively. FIG.38 shows an example of user defined PGC which refers to still pictureVOB. In the figure, cell#1 in the user defined PGC refers to stillpicture VOB group #2. Although the cell#2 in the original PGC refers tothe whole still picture VOB group #2 by specifying the first stillpicture VOB number and the last still picture VOB number in the stillpicture VOB group, the cell#1 in the user defined PGC refers to only astill picture VOB in the VOB group by specifying the second stillpicture VOB as the first still picture VOB number and the last stillpicture VOB number.

[0460] Assume that PGCI in FIG. 38 corresponds to PGC (or PGCI) 1446 inFIG. 3H. In this case, cell#1 and cell#2 in PGCI in FIG. 38 correspondto cells 1441 and 1442 in FIG. 3G. On the other hand, the first videopart in the RTR_STO.VRO file in FIG. 38 corresponds to a cluster ofV_PCK 1421 and SP_PCK 1422 in FIG. 3F. Furthermore, a video part thatfollows the first video part corresponds to a cluster of A_PCK 1423 andDM_PCK 1424 in FIG. 3F.

[0461] The characteristic features of the respective embodiments of thepresent invention will be summarized below.

[0462] *] One VOB or PTT can contain a plurality of pieces of stillpicture information.

[0463] *] Upon recording a plurality of still pictures, one VOB cancontinuously record at least two pieces of still picture information inan unrecorded area.

[0464] *] Cell information (S_CI) can designate a plurality of pieces ofcontinuous still picture information.

[0465] The effects of these three “*”s are common to the respectiveembodiments.

[0466] More specifically, a high-performance digital camera can recordseveral thousand or several ten thousand still pictures. Upontransferring data to an optical disc, the data are preferably groupedand recorded on the optical disc in units of a plurality of stillpictures, thus allowing easy processing and attaining short transfertime.

[0467] A high-performance digital camera can record several thousand orseveral ten thousand still pictures. When VOB information is prepared byconstructing a VOB for each still image, management information has ahuge size. The method of the present invention can greatly reduce themanagement information size.

[0468] Furthermore, since each still picture information forms adifferent file in the digital camera, management and search processesare cumbersome. In the present invention, since still pictures aregrouped in units of a plurality of pictures, management and searchprocesses are easy.

[0469] Since each still picture information forms a different file inthe digital camera, the contents of a still picture cannot be confirmedunless each file is opened. In the present invention, the user canconfirm contents as if he or she checked a positive film (or negativefilm) of photographs, as shown in FIG. 11, by grouping still pictures inunits of a plurality of pictures.

[0470] Furthermore, video information that stretches across a pluralityof video frames is recorded in units of VOBs. When a plurality of stillpicture information are recorded in units of VOBs, video information andstill picture information can be processed in a single layer (in asingle directory level in FIG. 2). For example, cells of both videoinformation and still picture information can be allocated in a singlePGC, thus allowing mixed display of video information and still pictureinformation, and broadening the expression range.

[0471] *] In the embodiment of the present invention, the VOBU map(S_VOB_ENT#) or VOB map is prepared.

[0472] *] The RTR recorder has an arrangement capable of recording theVOBU map or VOB map.

[0473] The effects of these two “*”s are common to the respectiveembodiments.

[0474] The user can directly access a still picture he or she wants towatch using the VOBU map or VOB map that records information such asrecording addresses in units of still pictures, and the access speed fordisplaying a plurality of still pictures can be greatly improved.

[0475] When a plurality of still pictures are to be continuouslydisplayed, seamless display (with continuous joints among stillpictures) can be achieved using presentation time information PTM and/orsystem clock reference information.

[0476] Furthermore, since the start addresses of V_PCK that records astill picture itself and A_PCK that records audio information aredescribed at different locations, high-speed access can be made if onlystill picture information or audio information is to be played back. Asa result, when audio information in a specific VOB is used to displaystill picture in another VOB (since audio information alone can beaccessed at high speed), seamless display can be made.

[0477] *] In the present invention, cell information (S_CI) designateseach still picture in a VOB.

[0478] For this reason, since each still picture itself can bedesignated upon playback (using the VOBU map or VOB map), high-speedaccess can be performed, and seamless display can be made when aplurality of still pictures are to be displayed in turn.

[0479] Since each still picture itself can be designated upon playback,management upon playback becomes very easy. For example, upon displayinga plurality of still pictures on the screen at one time, as shown inFIG. 11, the processing to be executed becomes simple.

[0480] *] In the present invention, cell information (S_CI) candesignate a plurality of pieces of still picture information indifferent VOBs.

[0481] For this reason, since continuous audio information in one VOBcan be used upon displaying another VOB, the expression range can bebroadened.

[0482] Furthermore, since continuous audio information in one VOB can beused upon displaying another VOB, common data can be used and, hence,the data size to be recorded on the information storage medium (opticaldisc 1001) can be reduced. As a result, the actual data size that can berecorded per information storage medium (optical disc 1001) can begreatly increased.

[0483] By only preparing new video object information for pictureobjects (S_AVFIT) corresponding to the already recorded videoinformation, the existing video information can be used in combinationwith still picture information without modifying video objects 1012themselves.

[0484] *] In the present invention, cell information is reproduced, anda still picture is played back using VOBI.

[0485] As a consequence, since cell playback information for pictureobjects (S_CI) can be set independently of video object information forpicture objects as management information of the contents of pictureobjects 1013, the playback order can be designated irrespective of therecording order of still pictures on the information storage medium(optical disc 1001), thus remarkably improving the degree of freedom inexpression.

[0486] *] The present invention provides an apparatus which reads outstill picture information or audio information from a memory, and cansimultaneously play back the still picture information and audioinformation.

[0487] When a plurality of pieces of still picture information indifferent VOBs are to be designated, or when audio information alone fora plurality of still pictures is recorded on another area, if V_PCK,SP_PCK, and A_PCK are played back in turn in units of still pictures,the frequency of access becomes very high, and it is hard tocontinuously display a plurality of still pictures in turn (due to theinfluence of the access wait time of the optical head).

[0488] By contrast, when information contents for at least two stillpictures of V_PCK, SP_PCK, and A_PCK are played back at the same time,and are temporarily saved in memory 1563, and the stored contents aredisplayed simultaneously with the playback timing of the remaininginformation, the frequency of access of the optical head can be greatlyreduced, thus allowing easy continuous display.

[0489] *] The present invention provides an after recording apparatusfor recording additional information to already recorded still pictures.

[0490] For example, when still picture information sensed by a digitalcamera having no audio input function is directly recorded on theinformation storage medium (optical disc 1001), the recording result hasa structure which does not contain any A_PCK (audio pack), as shown inFIG. 10I. A case will be examined below wherein the recorded informationis played back, and comments are added to still pictures one by one by“audio input via a microphone”, “overwriting marks by handwriting”,“addition of text information by key-in”, and the like, while displayingthem on the screen, as shown in FIG. 11. In this case, when therecording format is to be changed from the structure that does notcontain any A_PCK shown in FIG. 10I to a structure that contains A_PCKshown in FIG. 10F, re-recording must be done on the information storagemedium (optical disc 1001), resulting in cumbersome processes and a longprocessing time. By contrast, when additional information alone isrecorded as another VOB 1634 on the information storage medium (opticaldisc 1001), as shown in FIG. 10J, without modifying the data that doesnot contain any A_PCK (audio pack) shown in FIG. 10I, information can beadded to a still image very easily and quickly later.

[0491] The characteristic features included in the system of the presentinvention will be described in more detail below.

[0492] According to the present invention, an information storage mediumwhich is capable of recording and playing back at least still pictureinformation, and continuously records a plurality of still pictures, ischaracterized by having a first information unit [VOBUs 1641 to 1649]having one still picture information, and a first group unit [VOBs 1632to 1634 or PTTs 1407 and 1408] which is comprised of a set of firstinformation units, and has a plurality of pieces of still pictureinformation having different contents, and recording information in thefirst group unit.

[0493] Note that the still picture information includes at least one ofvideo information [V_PCK 1664 and the like], sub-picture information[SP_PCK 1682 and the like], and audio information [A_PCK 1693 and thelike].

[0494] The first information unit is constructed by at least one of aVOBU (video object unit) and VOB (video object), and the first groupunit is constructed by at least one of a VOB (video object) and PTT(part_of_title).

[0495] An information recording/playback apparatus according to thepresent invention, which is capable of recording and playing back stillpicture information on/from an information storage medium, comprises anunrecorded area detection unit [system controller 1530] for searchingfor an unrecorded area [unrecorded area 1460] on the information storagemedium, a still picture grouping unit [formatter 1556] for grouping aplurality of pieces of input still picture information, and aninformation recording/reproducing unit [informationrecording/reproducing unit 101] for recording the plurality of pieces ofgrouped still picture information on the unrecorded area of theinformation storage medium detected by the unrecorded area detectionunit. At least two pieces of still picture information [e.g., VOBUs 1642and 1643] of the plurality of pieces of grouped still pictureinformation are continuously recorded in nearby areas [e.g.,continuously recorded in extent#δ 1474] on the information storagemedium.

[0496] An information recording/playback apparatus according to thepresent invention, which is capable of recording and playing back stillpicture information on/from an information storage medium, has a firstrecording area [picture objects 1013] for recording still pictureinformation itself, and a second recording area [control information1011] for recording management information that pertains to a stillpicture. This information storage medium [optical disc 1001] has a firstinformation unit [VOBUs 1641 to 1649] having one still pictureinformation, and a first group unit [VOBs 1632 to 1634 or PTTs 1407 and1408] which is comprised of a set of first information units, and has aplurality of pieces of still picture information having differentcontents. Still picture information is recorded on the first recordingarea in the first group unit, and a plurality of still pictures havingmap information [VOBU map 1738 for picture objects or VOB map 1899 forpicture objects], which records management information that pertains toeach still picture information associated with the first informationunit, are continuously recorded.

[0497] An apparatus according to the present invention, which plays backan information storage medium capable of recording and playing back atleast still picture information, records still picture information andmanagement information that pertains to a still picture on aninformation storage medium, which has a first recording area [pictureobjects 1013] for recording still picture information itself, and asecond recording area [control information 1011] for recordingmanagement information that pertains to a still picture. Thisinformation recording/playback apparatus comprises a recording areadetection unit [system controller 1530] for detecting a location[unrecorded area 1460] where a plurality of pieces of still pictureinformation are recorded on the information storage medium, a groupingunit [formatter 1556] for forming a first group unit [VOBs 1632 to 1634or PTTs 1407 and 1408] by collecting a plurality of first informationunits [VOBUs 1641 to 1649] each having one still picture information, aninformation recording/reproducing unit [informationrecording/reproducing unit 101] for recording the grouped first groupunit on an area of the information storage medium detected by therecording area detection unit, a management information preparation unit[system controller 1530] for preparing management information [VOBU map1738 for picture objects or VOB map 1899 for picture objects] thatpertains to still picture image information in the first group unit, anda management information recording unit [informationrecording/reproducing unit 101] for recording the management informationthat pertains to still picture information, and is prepared by themanagement information preparation unit in the second recording area[control information 1011].

[0498] An information storage medium according to the present invention,which is capable of recording and playing back at least still pictureinformation, has a first recording area [picture objects 1013] forrecording still picture information itself, and a second recording area[control information 1011] for recording management information, and thesecond recording area has a first control information recording field[video object information 1107] that records information which pertainsto a recording state of still picture information recorded in the firstrecording area on the information storage medium, and a second controlinformation recording field [playback control information 1021] thatrecords information which pertains to a playback method upon playingback _104 still picture information recorded in the first recordingarea. In this information storage medium, minimum unit information [cellplayback information 1108] for playback of the still picture informationis recorded in the second control information recording field, and theminimum unit information designates a still picture itself to be playedback [still picture number 1875 in a VOB that records a video pack ofthe first still picture in a cell, and still picture number 1876 in aVOB that records a video pack of the last still picture in a cell, orstill picture number 1885 in a PTT that records the first still picturein a cell, and still picture number 1886 in a PTT that records a videopack of the last still picture in a cell].

[0499] Note that the information storage medium has a structure in whichthe minimum unit information [cell playback information 1108] recordedin the second control information recording field [playback controlinformation 1021] designates a plurality of pieces of continuouslyrecorded still picture information [by designating the first and laststill picture numbers in a cell, a plurality of pieces of still pictureinformation therebetween can be designated].

[0500] On an information storage medium according to the presentinvention, which is capable of recording and playing back at least stillpicture information, a plurality of pieces of still picture informationare recorded in the first recording area [video objects 1012] using afirst information unit [VOBUs 1641 to 1649] having one still pictureinformation, and a first group unit [VOBs 1632 to 1634 or PTTs 1407 and1408] which is comprised of a set of first information units, and has aplurality of pieces of still picture information having differentcontents. In addition, information [video object information 1107] thatpertains to a recording state of still pictures recorded in the firstgroup unit is recorded in the first control information recording field[control information 1011].

[0501] The minimum unit information [cell layback information 1108] forplayback of the still picture information and is recorded in the secondcontrol information recording field [playback control information 1021]designates a still picture [still picture numbers 1875, 1876, 1885, and1886] in a first group [VOBs 1632 to 1634 or PTTs 1407 and 1408]recorded in the first control information recording field [video objectinformation 1107] so as to play back still picture information. Also, astill picture position [still picture number j: VOBU 1828, still picturenumber h+j−2: VOBU 1829] in a second group [VOB#B 1822] different fromthe first group [VOB#A 1821] recorded in the first control informationfield is designated to simultaneously play back audio information orsub-picture information.

[0502] A playback apparatus according to the present invention has aninformation reproduction means [information recording/reproducing unit101], and an information display means [display/input panel 1548 of RTRrecorder]. The information reproduction means [informationrecording/reproducing unit 101] reproduces information that pertains toa playback method recorded in a second control information recordingfield [playback control information 1021], and then reproducesinformation that pertains to the recording state on the informationstorage medium, which is recorded in a first control informationrecording field [video object information 1107], on the basis of thereproduction result. After that, the information reproduction meansreproduces still picture information recorded in a first recording area[picture objects 1013] on the basis of the reproduction result, and theinformation display means [AV output 1546] displays the reproducedinformation.

[0503] A playback apparatus according to the present invention,comprises a reproducing unit [information recording/reproducing unit101] for simultaneously reproducing, from an information storage mediumwhich records a plurality of pieces of still picture information inunits of groups {VOB#A 1821, VOB#B 1822], and in which the still pictureinformation contains at least one of video information [V_PCKs 1852 and1854], sub-picture information [SP_PCK 1848], and audio information[A_PCKs 1865 and 1866], information for at least two still pictures[still picture number 2 and still picture number 3 (not shown), or stillpicture number j and still picture number j+1 (not shown)] of the videoinformation, sub-picture information, and audio information, a storageunit [memory 1563] for temporarily storing the information reproduced bythe reproducing unit, and a display unit [AV output 1546] forsimultaneously displaying information, which is obtained by reproducingthe remaining information of the video information [V_PCKs 1852 and1854], sub-picture information [SP_PCK 1848], and audio information[A_PCKs 1865 and 1866], which is not stored in the storage unit, by thereproducing unit [information recording/reproducing unit 101], and theinformation stored in the storage unit.

[0504] An after recording apparatus according to the present inventionuses an information storage medium, which has a first information unit[VOBUs 1641 to 1649] having one still picture information, and a firstgroup unit [VOBs 1632 to 1634 or PTTs 1407 and 1408] which is comprisedof a set of first information units, and has a plurality of pieces ofstill picture information having different contents, and continuouslyrecords a plurality of still pictures in the first group unit.

[0505] The apparatus using this medium comprises an additionalinformation input means [AV input 1542→ADC 1552/A encoder 1554 or SPencoder 1555] for adding information to each still picture information[VOBUs 1825 to 1827], a temporary storage unit [temporary buffer memory1534] for temporarily storing additional information added to each stillpicture information, an additional information synthesizing means[formatter 1556 and data processor 1536] for grouping the additionalinformation added to each still picture information into the first groupunit [VOBs 1632 to 1634 or PTTs 1407 and 1408], and an informationrecording means [information recording/reproducing unit 101] forrecording synthesis information prepared by the additional informationsynthesizing means on the information recording medium.

[0506] As described above, according to the present invention:

[0507] A) A new recording format and data structure of managementinformation, which can process a plurality of pieces of still pictureinformation while assuring data consistency and continuity of a generalvideo recording format and management information in a rewritableDVD_RTR disc which assures compatibility and continuity with DVD videodisc, can be obtained.

[0508] B) A new recording format and data structure of managementinformation, which can easily manage and search a plurality of pieces ofrecorded still picture information, can be obtained.

[0509] C) An information playback apparatus, which can seamlessly andcontinuously display a plurality of pieces of still picture information(continuity upon playback) by allowing high-speed access to aninformation storage medium that records a plurality of pieces of stillpicture information, can be obtained.

[0510] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

1. An information recording method for recording information on aninformation storage medium capable of recording and playing back atleast still picture information, comprising the steps of: constructing afirst information unit having one still picture information;constructing a first group unit which is composed of a set of firstinformation units, and has a plurality of pieces of still pictureinformation; and recording one or more pieces of still pictureinformation in the first group unit.
 2. An information recording methodfor recording information on an information storage medium, which iscapable of recording and playing back at least still picture informationand has a first recording area for recording still picture informationitself, and a second recording area for recording first managementinformation that pertains to still picture information, comprising thesteps of: constructing a first information unit having one still pictureinformation, and a first group unit which is composed of a set of firstinformation units, and has a plurality of pieces of still pictureinformation; recording still picture information on the first recordingarea in the first group unit; and recording a plurality of pieces ofstill picture data having second management information which pertainsto each still picture information associated with the first informationunit.
 3. An information recording method for recording still pictureinformation on an information storage medium, which has a firstrecording area for recording still picture information, and a secondrecording area for recording management information, which containsfirst control information that pertains to a recording state of thestill picture information, and second control information that pertainsto a playback method of the still picture information, comprising thestep of: recording minimum unit information for playing back the stillpicture information in a field for recording the second controlinformation, and designating still picture information to be played backby contents of the minimum unit information.
 4. A method of playing backinformation from a medium, in which one still picture informationconstructs a first information unit, a first group unit having aplurality of pieces of still picture information is constructed by a setof first information units, and which records one or more pieces ofstill picture information in the first group unit, comprising the stepof: sequentially playing back one or more pieces of still pictureinformation in the first group unit which is recorded on the medium. 5.A method of playing back information from an information storage mediumwhich has a first recording area for recording still picture informationitself, and a second recording area for recording first managementinformation that pertains to still picture information, and in which afirst information unit having one still picture information, and a firstgroup unit which is composed of a set of first information units, andhas a plurality of pieces of still picture information are constructed,still picture information is recorded on the first recording area in thefirst group unit, and a plurality of pieces of still picture data havingsecond management information which pertains to each still pictureinformation associated with the first information unit are recorded,comprising the step of: playing back one or more pieces of still pictureinformation recorded on the medium on the basis of the second managementinformation.
 6. A method of playing back information from an informationstorage medium, which has a first recording area for recording stillpicture information, and a second recording area for recordingmanagement information containing first control information thatpertains to a recording state of the still picture information, andsecond control information that pertains to a playback method of thestill picture information, and in which minimum unit information forplaying back the still picture information is recorded in a recordingfield of the second control information, comprising the step of: playingback one or more pieces of still picture information recorded on themedium on the basis of contents of the minimum unit information.
 7. Aninformation storage medium capable of recording and playing back atleast still picture information, wherein one still picture informationconstructs a first information unit, a first group unit having aplurality of pieces of still picture information is constructed by a setof first information units, and one or more pieces of still pictureinformation are recorded in the first group unit.
 8. An informationstorage medium which comprises a first recording area for recordingstill image information itself, and a second recording area forrecording first management information that pertains to still pictureinformation, and is capable of recording and playing back at least stillpicture information, wherein a first information unit having one stillpicture information, and a first group unit which is composed of a setof first information units, and has a plurality of pieces of stillpicture information are constructed, still picture information isrecorded on the first recording area in the first group unit, and aplurality of pieces of still picture data having second managementinformation that pertains to each still picture information associatedwith the first information unit are recorded.
 9. An information storagemedium comprising a first recording area for recording still pictureinformation, and a second recording area for recording managementinformation containing first control information that pertains to arecording state of the still picture information, and second controlinformation that pertains to a playback method of the still pictureinformation, wherein minimum unit information for playing back the stillpicture information is recorded in a recording field of the secondcontrol information.
 10. A medium according to claim 7, furthercomprising a recording field of after recording information associatedwith the still picture information.
 11. A medium according to claim 8,further comprising a recording field of after recording informationassociated with the still picture information.
 12. A medium according toclaim 9, further comprising a recording field of after recordinginformation associated with the still picture information.
 13. A mediumaccording to claim 7, further comprising a recording field ofsub-picture information associated with the still picture information.14. A medium according to claim 8, further comprising a recording fieldof sub-picture information associated with the still pictureinformation.
 15. A medium according to claim 9, further comprising arecording field of sub-picture information associated with the stillpicture information.